The following is what I learned from our recent trip to Costa Rica:
1. Trust the advice and recommendations from the experts on the forum, especially tours. We had some great tours (Manuel Antonio Tico Tours and Planet Dolphin in Manuel Antonio and Sky Trek and Eco Termales in La Fortuna). However, we probably had 2 of the worst tours of our traveling experience due to purchasing tours on the go in La Fortuna. They weren't mentioned on Trip Advisor, but sounded good.
2. Beef tastes much better in Costa Rica than in the United States. Perhaps it is because they con't use preservatives in Costa Rican meat.
3. The waiters/waitresses don't get all of the 10% tip tax charged to your bill. Please tip a little extra to your waiters/waitresses.
4. The food tastes great in Costa Rica. We never had a bad meal. The portions sizes are also generous.
5. People's expectations of beaches are different. I wouldn't go to Costa Rica for the beaches. In fact, I found the rip tide on the Manuel Antonio public beach and others to the north to be extremely strong - stronger than any place I have ever visited.
6. It was consistant when someone said the wak would just take 25 minutes you could always add on at least another 30 minutes.
7. I was amazed with the number of hostels. This is probably because the amount of backpackers, especially from foreign countries, who spend several weeks in the country.
8. I didn't realize how small the airport is in San Jose. The airport is easy to get around.
9. You are not allowed to take ground coffee in your check-on baggage. If you do purchase coffee in Costa Rica, buy it at a supermarket and ask the employees there for their recommendations.
10. We hired a private transfer with Tucan Limosine and would do it again. Excellent service and great people. The roads are narrower and signs difficult to follow at times. However, some people may like to drive themselves.