Arrival into Rarotonga is fairly straight forward. The airport process is pretty quick and easy.
Duty free is cheaper in Raro, and it's a good idea to take advantage of it, as it's the last time anything will be cheap while you're on the island.
Be sure to grab a few of the brochures while you line up and wait to go through customs, as these will come in very handy later.
It's best to arrange transport to your accommodation prior to arrival, as taxis don't line up outside like most airports. Your accommodation provider will likely offer to arrange you a shuttle which will probably cost you around $20 NZD per person each way. If you are offered a lay by your driver, savour this moment, as these 'local charm' moments are few and far between. They'll also have a map with coupons. Take it and make the most of the coupons. They can save you a lot of money on car/scooter rental etc. Expect to have to wait until the van is full before they will leave. This can take a while.
After checking into your accommodation, chances are you will want to organise yourself some wheels. Most of the vehicle hire companies offer free pick up and drop off. I can't speak for the other companies, but when we requested to be picked up by 'Island car & bike hire' we were told that there was only one person working and they couldn't leave. Unfortunately the wife of our accommodation provider worked for them and offered to drop us off, so we felt a little pressured into going through them. Their prices were average, their scooters were run down and poorly maintained, and their insurance excess was very high at $2000 NZD (or $1000 for an extra $5 a day) compared to $550 at other rental companies. A bit laughable considering the scooters aren't even worth that much. Our scooter decided to stop working half way through a trip the first day we had it and we spent an hour on the side of the road waiting for it to be fixed. We were lucky that a local policeman was parked on the road where it stopped working and he called the hire place, as if he hadn't we would have had a long walk ahead of us. Needless to say I wouldn't recommend that particular rental company. Your best bet is to make the most of the brochures and coupons and find the best deal. If you get there and they look like they're about to fall apart, don't be afraid to walk away and try somewhere else. If I had to choose again, I would personally go with Polynesian bike hire, as their scooters looked far more modern and well maintained. The hire company will also issue you a 24 hour temporary license, which you will need to keep on you until you go and get your Rarotongan license. Don't leave valuables under the seat of your scooter. Local kids know how to open them and will steal your things given the opportunity.
The Rarotongan drivers license is ultimately a souvenir produced by the government to scrape some revenue out of you. They don't recognise foreign licenses, so your license from home is useless, and apparently the local Police have a tendency to target tourists, so it's definitely best to get one. For this you go up to the Police station in Avarua (check your map from the airport) with your license, your passport and some money. Fill out the visitor application and jump on the end of the line. It costs $20-25 NZD depending on whether you have the class of license you're applying for on your home license. If you don't, you pay the extra $5, do a short test (drive to the end of the road and back) and you are presented with your Rarotongan license. It pays to turn up as early as possible, as the line is well out the door by lunch time and in the heat it is a very long wait. Don't forget your license and passport, and bring a pen!
Keep in mind the fact that the locals also obtain their licenses very easily, and are therefore very poor drivers. Avoid following them closely as they tend to not indicate or consider the fact that you are behind them when turning, and try to pay attention to cars on the side of the road, as they will frequently just pull out into the road in front of you. There are also dogs running loose all over the island which have a tendency to run out into the road, so keep an eye out for them as well. Seatbelts and helmets are not a legal requirement, and I was encouraged to wear neither by the locals, which I thought was a bit stupid considering the way the people drive. The speed limit is low, with a maximum of 50kph, so it makes having an accident unlikely, but if a car pulls out into you or a dog runs out in front of you there's very little you can do. The locals are also in the habit of drinking and driving, so it's probably better to be safe than sorry.
Petrol is expensive (around $2.50 a litre), but the island is small so you don't use enough for it to matter too much, and there are places to get petrol everywhere.
There are a few other things you may want to do while in Avarua. And I highly recommend doing them while you're already there.
If you're hoping to have communication with the outside world while on the island you have a couple of options. One is to stick with your home mobile provider and pay the roaming charges. My particular provider charged 79c for a txt message and a crazy $10 per MB of data if I were to want to access the internet on my phone, so I highly recommend making sure your mobile data setting is switched off on your phone before you arrive. You will also be charged if you answer international calls.The other option is to purchase a local Telecom sim card (the only provider on the island) from the supermarket in Avarua. The sim card costs $25 and you have to top up $10, but after you spend the $10 credit you receive 450 free international txt messages, which is quite handy. If you're wanting to use the internet you're best to make use of the wireless hotspots offered on the island. Most cafes have them and they all run off of the prepaid Zenbu system. You can either pay the person at the Cafe and they will give you an access code, or connect and pay with your credit card online. As far as I'm aware, if you get an access code from the Cafe staff rather than paying for it online, it limits you to using it at that particular Cafe, so keep that in mind.
The next thing you want to do while in Avarua is get your groceries. Be prepared to spend a lot more than you're used to for groceries in Rarotonga. The same goes for petrol, restaurants, shows and pretty much everything else available on the island. The cheapest place for groceries (except meat) is the CITC supermarket in Avarua. CITC hold a bit of a monopoly in Rarotonga, and all of the other places who sell groceries buy their products from CITC, so their mark up is ultimately a lot higher. Your other option for groceries is Wigmores Supermarket on the southern side of the island, but if you're doing a big shop then you may as well do it while you're already in Avarua. Generally you can expect to pay at least double what you would at home for groceries. If you need meat there is a place called Prime Foods in Avarua, which is the best place to get your meat supplies. There's also a market on Saturday mornings in Avarua where you can buy fresh local produce. Get in very early or everything will be gone.
The town supply of water in Rarotonga isn't recommended. Hopefully your accommodation provider supplies you with fresh water, but if they don't there are water fountains available on the island that provide free water that is safe to drink, or you can buy bottled water.
The heat may vary depending on what time of year you visit, but in the summer it's unbearably hot and humid. Hope for your sake that where you're staying has air con because fans simply don't do anything. It's never really sunny all day. It tends to cloud over and quite often rain after lunch time, and it generally rains at night, but the heat never leaves. When you are out in the sun make sure you have sun block on. You burn quickly here.
The other thing you should make sure you have on when outside is bug spray. Bugs are a fairly consistent problem in Raro. Mosquitoes will attack you all day long so have bug spray on you at all times and spray yourself immediately after a shower. There's nothing particularly dangerous wildlife wise in Rarotonga, but if you come across one of the centipedes (not to be mistaken for the harmless little black millipedes) which get pretty large, try to avoid it, as they pack a nasty bite followed by an even nastier sting. A local compared it to being stung by 15 wasps at one time. There's a good chance that you will come across geckos on the ceiling of where you stay. They're harmless, and they'll help keep the bugs away, but try to avoid leaving food lying around as they'll get into it and then poop everywhere.
If you're staying in a resort you may not have this problem, but if you're staying anywhere else you should definitely pack some ear plugs. There are chickens everywhere on the island and the roosters crow non stop through the night. If you get one outside your window you're in for a long angry night. It's definitely not something you get used to.
The obvious solution to the heat is to head to the water. The lagoon around the island isn't particularly great for swimming in most spots. It's mainly shallow reef that you will just end up stumbling around and cutting yourself up on. The only spots that I would recommend heading to are Muri and the Fruits of Rarotonga. Muri is the area where most of the resorts and tourist attractions are. The locals tend to avoid it, but if you're on holiday it is definitely where you want to be. There are several islands in the lagoon just off of Muri. The one directly out front with buildings on it is the only one you actually want to set foot on, as the rest are mosquito infested. The swimming right out in front in Muri is excellent. Clear water with plenty of fish and post card views with the islands out front. If you head south out of Muri you will eventually come across the Fruits of Rarotonga. This spot has the best snorkelling on the island. There are fish everywhere and plenty of reef formations to search around. The water gets to 3 metres deep here on high tide and is extremely clear. There are plenty of different fish species, moray eels and occasionally sea turtles. Save yourself the hassle of hiring and buy a cheap mask and snorkel before you get to Raro, as you'll probably use them quite a lot. The other way to view the fish in the lagoon is on one of the glass bottom boat cruises. The most popular being Captain Tamas. They take you from Muri around to the Fruits of Rarotonga, and know the best spots to go snorkelling. They're well known for providing a good laugh, and after the cruise put on a seafood meal and show. Be sure to make a booking, as they are very popular and sell out quickly. Again, don't leave valuables under the seat of your scooter, and try to avoid leaving anything valuable lying on the beach, as the local kids are known to steal things from there too.
At night another popular tourist attraction is the island shows. Several of the resorts around the island put on these shows, but personally I would recommend Te Vara Nui. As with most of the tourist attractions on the island, it pays to book in advance. They offer a free shuttle to and from the show, which is a good idea if you're planning on having a few drinks. Be prepared to stand around waiting for the shuttle for a while though, as ours arrived 20-30 minutes later than they told us it would. The show is very theatrical and entertaining, with island drums, dancing and fire spinning. They provide a buffet meal which is pretty much ready when you arrive, which saves you sitting around waiting on your meal, and means you get to the show faster. Dessert is provided after the show. Be warned that the dancers do come around at the end and try to get you to dance with them in front of everyone. If you're not keen, come up with an injury before hand, as they don't take no for an answer! You do pay quite a lot for the night out, with the standard dinner and show costing around $90 NZD per person. Add on top of that the drinks and it does end up hurting the pocket quite a bit. It is a good night out though, and when you compare it to going out to dinner at some of the restaurants around the island, who generally offer below par service at best, it's worth it.
Other attractions include Wigmore's waterfall (dry in summer), the hike to the top of the island, fishing charters, island safaris and hiring things like kayaks and stand up paddle boards. I was told to avoid the island safaris, as they show you very little that you can't just see yourself, but they all have brochures and you can pick and choose what appeals to you.
Now to the negative part of Rarotonga.. The people of Rarotonga. We went to one restaurant in particular called the Little Polynesian that basically sumed up the experience with the local people of Rarotonga for us. We were seated outside on quite a windy night, too far from the light of the restaurant to read what was on the menu let alone eat a meal. There were 2 tiny candles on our table that the waiter didn't even bother to light. A while after we arrived a local couple turned up who had clearly not made a reservation. Within about 10 minutes they were moved to a nicer table, even though there was already a couple waiting who had been there since before we arrived, and had already asked if they could be moved. The local couple received their food almost immediately, and the staff stood around talking to them, leaving everyone else with no service at all. The couple that asked to be moved ended up getting up and leaving because they couldn't stand waiting any longer. It took about 40 minutes for our starter to arrive, which was literally 4 pieces of bread and 2 small trays of dip, and an hour for our actual meals to arrive. In the time that we were waiting, our waiter made no attempt to ask us how we were doing, if we needed new drinks, or say anything. He couldn't manage to crack a smile or say a single extra word that he absolutely didn't have to, and this is where the bad part of Rarotonga lies. Unfortunately the waiters attitude is what you come to expect from the bulk of the locals on the island. With the exception of some of the people working on the tourist attractions, the locals are extremely unpleasant people. They make it very clear that they don't like tourists, which is ironic considering most of them make a living off of them. They rarely smile and make no attempt to be polite. Expect to be greeted with scouring faces and unpleasant attitudes from the locals from the moment you arrive until the moment you leave. The local attitude really puts a dampener on the whole experience of Rarotonga, and my recommendation would be to just stay within the tourist friendly bubble of Muri and avoid wasting your time or money elsewhere.
To sum up my experience of Rarotonga, it's a beautiful tropical island that is unfortunately let down by the attitude of the local people. Stick to Muri and the strongly tourist based attractions and make the most of the snorkelling and water rather than venturing out around the island.