The best hotel to stay at is the Emory Conference Center. This is adjacent to campus and so an easy walk into the lab.
University Inn is 2nd best; it's not affiliated with Emory. It might be cheaper and if that's a concern, then this location is fine.
Some people stay in downtown Decatur, which is a nice area with lots of restaurants that are easy to walk to. Two hotels there are the Courtyard Atlanta Decatur and the Hampton Inn & Suites Atlanta Decatur/Emory. If you're there, it will be harder to get to Emory, although there is a free Emory shuttle bus that leaves from a couple blocks away, at the MARTA station bus area. This shuttle is available for anybody to ride, you don't need an Emory ID, the Emory shuttle system is intentionally open to the public.