We also use the above sites. We have booked mostly State parks in FL and even though ReserveAmerica has photos, we sometimes find
http://www.campsitephotos.com helps as well. The internet is invaluable!
This is our first real snowbird season and online we've reserved one week stays at Myrtle Beach, Fort deSoto, Long Key, Jonathan Dickinson, St. Augustine, Panama City - two weeks at Sebastion Inlet - three in the Bradenton area (split between Lake Manatee and Manatee River and a month at Williston Crossing. We're moving around quite a bit but as newbies that's fine with us.