Since nobody has mentioned it yet, take a look at AquaMarina Suites. True they are suites w/ full kitchens, maybe more than you need, but a good deal if you are staying a week or more, I think you'll get a break for the longer stay. All rooms have balconies looking at the ocean (some better view than others), pool, nice little pool bar, plenty of shady spots by the pool. Right at the north edge of town, plenty of places to eat within walking distance. We just stayed there and we loved it. Just more info to confuse you
Banana Beach has a lovely restaurant. It is pretty pricey, but we really enjoyed our meal there. Worth doing, as there are so many other relatively inexpensive, good places to get a bite.
re: snorkeling, not expensive to go by by boat($25 - 30 US PP), several good operaters around. Seaduced, Searious, Bottom Time, etc. are all good. The closer spots on the reef will take only 20min or so to get there. Snorkeling is also good under some of the docks (no boat needed); some have artificial reefs built under them. The docks at Belize Yacht Club and Ramon's are like this; well worth doing...
Good luck trying to filter all the info
Plenty of good places to stay, actually I think it's hard to go wrong unless you have very specific needs / preferences..