We highly recommend the walking tour of Corkscrew Swamp Sanctuary -- it's off the beaten path, but totally worth seeing. A 2-mile wooden boardwalk takes you through the sanctuary, where you view various types of terrain and wildlife.
We saw various herons, owls, lizards and alligators. The Audobon Society guides set out early in the morning with telescopes and binoculars, and they set them up pointing at the most promising nests for public viewing. The gift shop is (literally) a hoot, too!
Also at Corkscrew Swamp Sanctuary, we met Rod Wiley, Everglades wildlife photographer par excellence. He had an exhibit at the Visitor's Center. His photos captured the personallity of each creature like nothing I'd ever seen before!