According to the Georgia Department of Transportation, drivers should slow down when approaching a roundabout and be mindful of posted speed limits. Pedestrians always have the right of way; drivers must stop to allow them across. For cars approaching the roundabout, vehicles already in the roundabout have the right-of-way. Those entering the roundabout must yield to this traffic. Look left and drive into the circle when there’s a safe distance between vehicles. Once in the roundabout, do not stop.
Video explanation of roundabout rules from the U.S. Department of Transportation: www.youtube.com/watch?v=peUf2NRdWxs&t=2s.