Well, Taco Mac is an Atlanta staple. They are everywhere and usually have a pretty good selection.

My favorite is Brick Store. They have a gigantic selection of Belgians and always some interesting local stuff on tap. If you like chicken salad, get the melt. It goes great with a beer or two ... or five.

Porter Beer Bar in Little 5 is great too. Fantastic selection of local and a lot of hard to get stuff from just about anywhere.

If you want to do any brewery visits, there are plenty. GA just has odd beer laws that don't allow anything other than tastings so if you go to one, you'll get tickets for tastes and it will only be for a limited time. Now don't take that to mean not worth going to, they definitely are, just don't go starving and pay attention to the hours of the tasting. They aren't all day places you can just pop in.

Take a look here: http://www.beeradvocate.com/place/city/1/

I've been to them all so feel free to ask if one looks like your type of place.

They won't be expensive. $5 - $8 for a glass and $8 would only be for the really special stuff.