Rent a car. Cars are the best tools on the island. Remember that all cars have the right of way, and most damage is on the right front end of all vehicles. Drive like you are in the city! You can cover the island by vehicle in a couple of hours, unless you stop by the nude beach--nothing like it! I even got applause from a couple of ladies! The beer of the island is Caribe (like Corona). You can buy them for a dollar, and you can drink and drive! Finish your beer, and another little stand is on the side of the road. The gas stations even have bottle openers for your convenience. Check out the resorts on both sides of the island--there are some real beauties. We drove up to the highest point on the island, where the road was about as wide as a VW and straight up.
For food, the French side tends to be more pricey than the Dutch side. We were budgeting, but we ate very well, and conch is the ticket! If you can get it, try the guava-berry rum . . . good stuff. We got some bootleg from a local guy who gave our resort an island tour. We had nine folks, from their early 20s to late 60s. We partied so much, we were 3 hours late returning and the folks at the resort thought we ran into trouble!
The catamaran cruises are great, too--I don't rememeber much after the champagne and sixth rum-runner, but we had a blast!
One drawback is tourist season. I could NOT imagine getting around as easily as we did if it were tourist season. There are only so many roads that you can access. Also, be careful with the locals . . . we were constantly warned about theft, etc. Other than that, a great place!