While we usually enjoy unplanned and unsupervised disasters, I highly recomend a full agenda of Ranger activities as part of a trip down to the park. I even recomend the guided canoe trip (for the price it beats the hell out of lugging your own boat or even renting one on your own).
The bottom of the mainland is a totally uninhabited wilderness (think Christopher Columbus....well maybe not THAT wild).
The middle half of this expanse is covered by the wilderness waterway. For the rest you're on your own. Well almost. Everglades National Park has opened two new coastal campsites east of "The Waterway", and there's always been Nest Key...but it's a heck of a run from Shark to Nest. And there is no legit campsite in between. We're working on it but it could be a while.