So you've stayed at the scene of the crash, called 911, and decided not to be a raging jerk to the other driver involved. What else do you need to do? For one, don't forget to properly document the wreck and get the right insurance information from the other motorist.
Try to clear your head and figure out exactly what happened. What were you doing just before the crash? What street were you on, and in what direction were you headed? When did the other driver enter into the picture? You'll need to have a consistent and accurate account of the wreck to give to law enforcement and insurance providers. You may even find yourself telling this story several times.
Generally, you'll need to get the other driver's name, address, insurance company name and policy number. Make note of the make, model and color of vehicle they were driving as well. Don't forget to write down the other vehicle's license plate number, too. Were there any witnesses? If so, get their names and phone numbers. If you have a camera, take some pictures of the crash site. Those may come in handy during the claims process later on.