At a roundabout, which combination of signs, markings, and right-of-way behavior is correct?

1. Enter from any lane, stop in the circle, and pass slower vehicles
2. Drive clockwise unless a police officer is present
3. Treat the central island as a passing area if traffic backs up
4. Choose the proper approach lane, slow to the posted/advised speed, yield to pedestrians and traffic already in the roundabout, and travel counterclockwise