Also check your household insurance - you may have legal cover !
If you are not injured, things are easier. Get the driver's details and contact his insurance (assuming you are not involving a solicitor).
Has the driver admitted liability - if not, get a solicitor !
Write down what has happened - e.g. on Word and save it - note time, weather and visibility. Take pictures of the damage to all property, and yourself. Possibly take pictures of the accident spot.
If injured, pay a visit to your GP, and also I'd strongly recommend reporting the accident to your local Police station, even if it is for statistics. Most likely they will just log it and gve you a reference number.