This question has come up here before so try using the upper left hand search box to turn up some of the older threads. I have not been in Atlanta for some time now, but it seems like the best deals on rentals were to be found at FBOs at RYY, LZU, and FTY. PDK was and probably still is the last place to go if you want to keep training costs down. Too much focus on the rich Atlanta business crowd. They do have a nice restaurant and pilot shop there. I have not lived in this area since 2006, bear in mind. I would Airnav up these airports and see who lists flight schools and airplanes for rent and call them.