1. First make sure you and anyone in the car with you is ok
If you think there is an immediate medical emergency call 911 and request an ambulance.
2. Call the police and report the accident
Though the police report is inadmissible in court it is still a good starting point for documenting the accident. In situations where you have to utilize your Uninsured Motorist Coverage (UM) the policies often require reporting the accident to the police. Whether the police come or not is not required, just have to report it.
3. Get all the information about the other driver
Take a picture of their drivers license, vehicle registration, license plate and insurance card.
4. Take pictures of everything
Take pictures of all the damage to your vehicle and their vehicle. Take pictures of the area where the accident happened and of any debris on the ground from the wreck. Take pictures of the other driver (you would be surprised how often people deny being involved in an accident).
5. If still in pain follow up with medical providers so that the pain and injuries are documented
The insurance company is not going to just take your word on it. They need documentation.
6. Track all your expenses
Any out of pocket expenses (i.e. medical bills, car rentals, etc.) and any time lost from work as these can be added into the case.