I've just returned from a week in San Pedro and having used this site **extensively** beforehand, I offer the following advice for any newbies heading to AC or thinking about it:
1--stop thinking and go. You won't be sorry.
2--once you've made up your mind and booked your trip and get on the plane, leave your type A, control-freak, time-sensitive tendencies at home. I am all of the above and I left these all behind and didn't miss them one bit. Go with the flow, get into the Belize spirit of "whatever Mother Nature has in store for us today, we will see." Enjoy what's there, and don't worry about what isn't there. Sure, there's mosquitos, but heck, you're in Belize! Being in Belize overrides the bugs by far!
3--get into the local spirit. Talk to everyone and ask their names. They will ask yours and use it. I was walking down the beach on my 2nd day, when someone called my name and waved to me. You feel right at home.
4--don't be intimidated by things that are foreign to you, but enjoy the ride! There's a guy in the airport who will offer to get you drinks, shine your shoes or give you a pedicure. There's a guy biking along the beach selling a seaweed drink out of a cooler. It's all part of the journey and it's great fun to be part of it.
You have your choice of hotels and tours and operators, and I'm sure everyone has an opinion on which is best, so I doubt you could really make a poor choice. That being said, I stayed at the Palms and loved it and would probably not stay anywhere else. I used SeaDuced exclusively for my tours only because we had so much fun on the 1st day with our guides.
I'm already planning next year's trip and considering how I can spend more time there!