Stop and Notify Police. The law requires that you stop at the scene.
If people are injured call for an ambulance (911 will get both police and ambulance).
Do not attempt to treat an injured person unless you have first aid training.
Do not try to move an injured person unless it is a life threatening situation.
Exchange your name, address, insurance company name and ID number with the other driver.
Get the name and badge number of the investigating officer.
Other than the exchange of required information have no discussion with the other driver.
Tell the police officer your version of the accident.
Get the names, phone number and addresses of any witnesses.
Get your injuries cared for immediately. Tell the examining doctor every complaint and injury, no matter how minor. A serious internal injury may not show immediately.