After you have been in an accident, there are several things you should do to protect yourself. First, if you are injured, you need to receive medical attention immediately.
If you are not injured, but the damage to the vehicle(s) is significant, you need to contact the police. While you are waiting for the police and before the vehicle(s) are moved, it's a good idea to take photos of the accident scene.
Most cell phones have a camera application that you can use to photograph the accident scene and the vehicle(s) involved. These photos may prove to be an asset when dealing with an insurance company or when a personal injury claim is filed.
If possible, it's best to take a variety of photos. Take photos of your vehicle and any other vehicles involved in the collision. Be sure to get photos of the damage to each vehicle. If there are vehicle parts or shattered glass on the road, photograph that. If there are skid marks on the road, be sure to snap a couple of shots of those. You also want to be sure to get the accident scene as a whole, from several different angles as possible.
Try to include photos that show the weather conditions (i.e. if there is snow or ice on the road, or if the road is slick from rain) and where the accident occurred (in an intersection, at a stop light, etc.).
When taking photos, be sure to take some up close (of the damage) and from a further distance away to provide more detailed information. If you have sustained injuries, have someone also take photographs of them.