To get there on MARTA, take a red or gold line train to the Midtown station. All northbound and southbound trains stop there. From the main station exit, turn left on 10th Street and walk just over a block to the hotel. If exiting via the Federal Reserve, turn right on 10th. The Federal Reserve exit will put you on the same side of the street as the hotel.
Bus 12 departs from the station and also stops at the hotel. It is free to transfer from a train to a bus.