From Athens, take 78 South. It is about 15 miles north of I-20.
If you go to www.mapquest.com, request driving directions, and use Aonia, GA as the destination, it should get you there.
The track is actually before you get to the town of Aonia if you're coming from the north (Athens) on the right side of the road. It might even have a yellow sign with black letters, if I remember correctly.