The best hotel to stay at is the Emory Conference Center. This is adjacent to campus and so an easy walk into the lab. This includes the conference center and also "Emory Inn", they are at the same location and both are mentioned on that webpage.
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.
Farther from campus is Hampton Inn / downtown Decatur. 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.