How do you find them? I have a few books on FL dive sites and only the big springs are mentioned.
Excellent source of info:
Amazon.com: Diving Guide to Underwater Florida (10th Edition) (9781878348296): Ned DeLoach: Books
Another good source. It does focus on caves and caverns, but many of these sites allow OW diving as well.
Florida Cave, Cavern, and Sinkhole Diving
Call a local shop and ask. American Pro in Crystal River and Dayo in Orlando come to mind just to name a few.
http://www.americanprodiving.com/
http://www.dayo.com/