Please, Please, Please live in the east atlanta neighborhoods, or anywhere inside the perimeter. Decent cycling in the residential neighborhoods where sane driving is most likely; Reynoldstown, Grant Park, Little Five Points, Candler Park, Emory, Decatur, Midtown, Downtown, and the Stone Mountain path are pretty nice. Atlanta is pretty flattish on the whole, though the more north you go the hillier it tends to get, outstanding exceptions like North Ave. tend to make people complain. Road conditions vary between mildly annoying to nice, that's the upside of a generally car-focused city. Beware the giant metal plates in the rain, however. If I were choosing a place to live, I'd probably go for Decatur if you want a longer ride, or Candler Park area if you want a quicker one. Assuming you're headed downtown.