My brother just got back about a month ago, a few pointers he gave me if I ever went were...
First thing you do when you get there is rent a moped scooter to get around the island. This avoids taking the cab rides which are expensive. It's the same price no matter if you are going from one side of the island to another, or going 10 feet. If you do happen to take a cab, do not ask them to bring you to the island's best anything, restaurant, bar, ect. These cab drivers get cuts from different places if they drop people off there, even if the place sucks. Do your own research. He told me the best restaurant he found was some place on one of the beaches, don't remember the name though.