Arrived on Praslin at 9am via plane (15 minutes) - highly recommended as the views flying out of Mahe and then over Praslin are awesome. Went through a travel agent who arranged local pick ups from the airport and hotel through Masons. Masons was spot on time and made sure that we were booked into the hotel and even confirmed our outgoing flight for us. They were excellent in this regard but their day trip options are expensive. We ended up going on day trips on our own which was much cheeper and easy enough not to warrant spending the extra money. Here are some of the highlights:
Bus trips: the busses are on time and pass Paradise Sun every 30 minutes so there is never a long wait. They run from early morning till 6pm. Prepare yourself for a rollercoster ride - the roads are narrow and the busses GO! Catch the bus to Anse Lazio but don't get off at the stop for Lazio - take the bus up the hill to Zimbabwe (if you like a bit of adrenaline). It is just a 10 minute detour but the views are awesome. From the Lazio bus stop you have to walk down (and then up again) quite a steep road but do get there it is beautiful. There is also excellent snorkeling along the rocks.
Day trip to La Digue: must do! We caught the 9am ferry ($20 return - works out cheeper if you have Euros) and rented a bike when we got there. Do not take the bikes offered on the pier as the guy tried his luck by asking $20 - there are many other places to rent just behind the jetty for less than half. We paid 40 rupees. You can see the entire island in one day - cycle to grand anse (wild side), go snorkel at anse severe and cylce all the way to the end of the road on the other side of the island as it is deserted and beautiful. All in all it worked out way cheeper than the $65 asked by Masons.
On Praslin the local shops are much cheeper for drinks than the hotels and we ended up buying all our snacks, water etc there. Cigarettes are not always easy to find and unless you like Benson & Hedges, Marlboro or Capital (all strong) take your own. Same with alcohol: we took spirits and wine with and just got cooldrinks for mixes there.
Valle de Mai: worth visiting but we saw some pretty awesome palm forrests in other spots too. But it is a nice morning outing.
Diving: used Whitetip divers at Paradise Sun. They were very professional and friendly. They do two dives a day at 9am and 2pm. We did 3 dives - all of which were within 10 minutes by boat and max depth was 17 meters. This meant that the dives are nice and long 60 mins). I took a full suit and was glad that I did cause eventhough the water temp is 26 degrees it gets chilly after 60 minutes. Don't despair as you descend - it looks barren - but the diversity was awesome. Saw loads of lionfish, box fish, stone fish, emperatus, tangs, eels, powder blues, whitetip reef sharks etc etc. Highlilght was a school of bumpnose parrotfish the size of buffalo - OK maybe not quite but they were as big as me!
On our last day we rented a car for the day ($50) which was nice as we went all over and back to some favourite places. A car was nice however it is not essential as the busses are good and will get you everywhere you'd like to go - except up the hill coming back from Lazio!
We were on a breakfast and supper deal with Paradise Sun so did not eat many lunches on the island but the prices vary widely. Paid 40 rupees for a pizza and 120 rupees for calamari/chips/salad/fruit salad/coffee - but the portions are huge so my husband and I shared and it was more than enough.
I have read other reports on sand fleas etc but other than the occasional mosquito we did not see many bugs or any sand fleas. Having lived in Malawi and Florida we were surprised at how few creepy crawly biting thingies there were as the island is quite wild with loads of forrests.
All in all I can well recommend a trip to Praslin - it is beautiful, easy to get around, safe and offers the best of both worlds: forrests and ocean.