Although I marked this trail type as "singletrack" there is really only a couple miles of actual singletrack - the rest is grassy doubletrack. From the parking area, head around the gate and ride around the left side of the lake - this is where the 3 singletrack loops start. Once you've ridden all the singletrack, head out onto the doubletrack for a fast training ride.
From Milledgeville, take US 441 South a few miles. Turn left on Carl Vinson Rd. and the trail is on the right about 1.5 miles away (past the prison and the DMV).
http://www.singletracks.com/item.php?c=1&i=3265