You will need the registration for the vehicle
You will need you Qatar driver's license
You will need proof of insurance and if you have 100% coverage depending on the type of accident.
It will cost you for the paperwork. My windshield crack cost me 110 QR because there was no second party involved.
Madinat-Khalifa Traffic Police was very fast and efficient and so is Airport Traffic Police on "E" Ring and Tadmur St.
Look for number machine although I think some do not use them anymore.
You can only pay with a credit card or debit card, they DO NOT take cash. There is usually someone hanging around that will let you use their credit card for a small fee.