Hi. My husband (RobertE) and I were there last September for our first trip. You can expect to have a million and three things to do. We especially enjoyed the snorkeling at Hol Chan and Shark/Ray Alley. We also enjoyed the trip to Lamanai, but I'd suggest Altun Ha for the first venture to the ruins.
A nice relaxing dinner at Capricorn is a MUST! You'll have to get there by water taxi if you're not staying above the cut. We also enjoyed the BBQ on Sunday at B.C.'s. The folks there are great the BBQ is great. Also Banyan Bay palapa bar serves up a delicious Stewed Belizian Chicken. (My husband is still trying to replicate the recipe!) <grin>
We're not anglers, so I'm going to rely on Pescador's review of the fishing. Met him while staying at The Palms and he's a pretty serious fisherman. "Tarpon fishing with Nesto Gomez: This guy is incredible. "Eyes of a hawk". Although no fish were landed (my fault) Nesto put me within casting range of at least 50 fish!!!"

This time we're going to take the cave tubing excursion on the mainland. We're going back in July...only this time we're getting our scuba certification and will be spending much of our time diving.
Have a fantasic trip! We'll be back on Ambergris Caye July 5 -14 and can't wait!
-Laura-