I would bring your log books as the dive OP might require them to show experience/# of dives.
My advice to you would be to slow way down when diving. You will be looking for micro life since over-fishing takes a lot of the larger fish out of the equation.
I wear a full 3mm suit, and was cold on several of the dives (I've been in Jamaica somewhere between 6 and 10 times at various times of the year.). You should be able to rent a shorty to wear over a full 3mil suit.
Get out of the resort and experience some of the local food. You won't regret it. Koyaba and LTU are my favorite places to eat.
The beaches are public property, so expect to be solicited by the locals. My best advice is to politely say "No tanks mon". They can be rather bothersome (i.e. irritating), but just be firm and polite.
Shallow Plane: Has a small Cesna (or some plane like it) just off of the reef. Popular site, but not great.
Middle Shore is a decent dive.
Shark Reef: Great place to see a ton of juvenile fish.
Turtle Dive: Also another great place for micro-life.
Throne Room: The only place where I've seen dolphins.
Arches: Popular spot, but I don't remember much about it.
Gallery: Starting from the middle of the reef, you'll find great swim-through's. Great topography with huge barrel sponges/groups of fish.
Spadefish Reef: Can't remember.
Fish Pond:Can't remember.
Sandals Reef: Can't remember.
Bloody Bay Deep: As you can guess, it's a deep dive (40m) (130+ft).
Kingfish: Not many fish here, but the reef is in the best condition of any area. The reef looks like large mountains. About a 27 meter dive (90Ft).
Deep Plane: Yep, the name explains it all, but I don't remember much about it.
The Hunt: Decent place to run into Nurse Sharks.
Throne Room: Saw my one and only turtle here.
Golden Gate: Lots of swim-through's, but an equal amount of dead coral.
Hunt: Also a good place to see Nurse Sharks. Good site.
The Valley: Great diversity of critters here (Drum's, Grunts, Blenny's, Flounder...).
Mid-shoal: Tons of critters.
Arches: Good place for night diving.