Old Cow,
Here is my suggestion as to how to set up your local tax for Georgia.

1. I would set up each county in Georgia as a zone (sorry this is a long process but it really is the best way). This doesn't actually require the Local Tax mod to do.
There are detailed instructions in the readme for the Local Tax Mod on how to do this. You could also check out the forums to see if anyone else has already done this for your state, it might save you some time.

2. Use the Local Tax Mod to set up the special Atlanta tax by zip code.

I hope that helps.
Let me know if you have any questions.

LadyHLG