get the lonely planet guide book for Belize. it is great- tells about all the places you mentioned. we just got back from our first trip and it was like having a bible. we stayed at Captain Morgan's Retreat on the north end and loved it. just couples, quiet but alive with a great bar, restaurant and all amenities including their own reef they created to snorkel. use of their kayak is complimentary and it is easy to get all places from there.if you take excursions book them yourself though they are expensive through CM's Caulker has a population of about 700 and is known at the backpackers island. we day tripped there and found it pretty neat, but don't think i could stay a week.