My buddy and I did the 8.5 mile paddle from Riverbend Park to Jonathan Dickinson State Park in Jupiter, FL. There is no shuttle service here (as of right now, may be one in the future) so you have to drop a vehicle at the State Park (entrance fee) and then shuttle back to Riverbend.
The first couple miles is a tight and twisting route through a thick cypress forest. Very cool scenery with plenty of birds, turtles and a few otters and alligators. There are two dams with portage walkways around them. A few downed trees will cause you to duck down into the canoe to get past. About 2/3 of the way down there is a large cypress tree that has fallen across the river. You must lift the canoe over the tree to get past.
Shortly after is Trapper Nelson's camp which is maintained by the State Park. After the camp the river widens and is open to slow boat traffic. The last 2 miles are open pine forest with a few cypress and oak trees scattered around. Gradually the river becomes lined with thick mangrove trees as you near the boat ramps of Jonathan Dickinson State Park.
Plan on a 5-7 hour paddle depending on how many stops you make along the way.