If you will go to
www.atvnation.com/forum/index.php?showtopic=7406 it will list GA riding areas. Public at top and private at bottom. You will have to click on the private ones to see where they are. These are listed by the GA ATV Riders Assn. (Possum Patrol) so all of the places listed are ATV friendly.
You can also go to
www.atvpathfinder.com and click "United States" then scroll down to Georgia and it will list all of them.
They are also listed on GA Offroad.
www.georgiaoffroad.com but that is a dirtbike site and a lot of them seem snobby towards atv riders. They have a lot of info on the places to ride though.
Wish I could help you more but I'm on the opposite end of GA.