Look for the covered awning on the left side of the church (you can't miss it from the parking lot) -- this will lead you right into the Fellowship Hall. If you come in through the narthex (where the two sets of double doors are), turn left at the signpost, through the double doors, then right into Fellowship Hall. Follow your nose to the coffee smells.
If you need directions to the church, here's a handy map.
From I-285/Perimeter Freeway, take Exit 28 and proceed east (left turn from the inner loop, right turn from the outer loop) on LaVista Road. We're about a mile ahead on the left.