Stevedec beat me to it. Use google then check tripadvisor reviews.
Late to the party but for future reference:
Springhill Suites by Marriott is literally across the street from the mall at $109/night.
There are also a couple of hotels one exit north of the mall on I-985 (exit 8), but I do not think they are suite type hotels like you requested.
Alpharetta is one of the worst areas to get to and from during rush hours.Edited: 01 September 2014, 19:00
This request was from 2012.