Entrance costs $5 per car (less for a cycle or on foot). A well-maintained road runs the length of the Refuge and you can stop wherever you like. You can also park the car and walk along several trails. If you keep your eyes peeled you'll see lots of wonderful things. I visit at least once every time I'm in Florida and always see something different. I've even seen a couple of alligators.
I would recommend visiting either early morning or early evening, when the birds are more active. The Refuge is open every day except Friday, from 7:30am until sunset.

