Rangers serve most of the area and all campgrounds have resident volunteers who are good sources of information. There's no single admission fee and no one number to call; day-use areas are generally open 8am to 8pm. Pick up free literature and maps or buy a topographical version at any of the visitor centers, all open 8am to 5pm.
Pittman Visitor Center On the major throughway from Orlando and Mount Dora.
Salt Springs Visitor Center In Salt Springs, accessible from Jacksonville and Palatka.