Remove yourself from the flow of traffic in order to reduce the risk of another accident. Make sure you pull over to a safe place where you and the other driver can get out of your cars. For added safety, turn on your hazard lights once you've pulled over. Pay attention to where the other car is pulling over. If the other car does not pull over, try to view and remember their license plate once you are stopped on the side of the road. Write the license plate number down as soon as you can. If you or any of your passengers have any serious injuries, call 911 immediately to have paramedics sent to the scene. Attend to any minor injuries as best you can. It's very important to let paramedics know exactly what sort of injuries they will be dealing with when they arrive at the scene. The police will need to file a report of the accident. If there is any worry that harm may have been caused, the police will serve as a neutral third-party and document the scene of the accident. If the other driver drove off, you can tell the police their license number once they arrive. In some cases, the fender bender seems so minor that both parties avoid calling the police and simply exchange car insurance information. However, it's very important to have a police report of the accident filed for insurance purposes. After you've both pulled over, walk over to the other car and ask if the driver and their passengers are ok. Without getting angry or upset, assure them that police are on their way and that situation will be taken care of. Take a few deep breaths and try to avoid anger in this interaction. Staying calm will reduce the likelihood of other altercations. If the other driver is angry or belligerent, retreat back to your own car and wait for the police to arrive. Do not engage them in an uncivil way.

Summary:
Pull your car over to the side of the road if it's safely drivable. Check yourself and others for injuries and call emergency services. Call the police to the scene in order to assess the situation. Communicate with the other driver to make sure they're safe and calm.