I've always said that the best way to see a city is by foot, and although Atlanta has long distances to drive, the interior of the city is a 22 mile Photowalkers dream.
The Beltline wraps around the city and while you don't have to walk all 22 miles of it, you can pick and choose and have a great time out with your camera.
My favorite part of the Beltline is spotlighted in the latest #PhotowalksTV episode, starting at the Jackson Street Bridge to photograph the dynamic Atlanta skyline, and then continuing for about two miles on Freedom Parkway and then the Beltline. You'll end up at the Ponce City Market, a wonderful collection of shops and restaurants in an old, converted Sears building that goes back to 1923.
Have fun walking!