My best recommendation is a good travel guide book for the Western Caribbean. Kay Showker or Arthur Frommer had the best books in my opinion, but Lonely Planet has been referenced too. Caribbean Ports of Call is another book, but you want to make sure that your western itinerary ports are included. Doing research before you travel is half of the fun and makes the time go by. When your tour booklet arrives, you will be ready to book a tour or will have had time to book on your own.
Location: Wisconsin....about 100 miles south of the Frozen Tundra and 70 miles east of Camp Randall
Re: Maps of islands and weather?
For Cozumel you can get all this information at <http://www.cancun-map.com> It's got weather, things to do other than ship-sponsored excursions, etc. It also as a distance calculator where you can calculate how far someplace is in miles or kilometers.