1) Stop as soon as you can and move your vehicle only if it is safe to do so. There's no need to unnecessarily hold up all the other traffic. If the positions of the vehicles involved in the accident are important to preserve, take photos of the scene then move if it's safe to do so.
2) If anyone is injured, call 911 and inform the police. If there are no injuries, or relatively minor complaints, the police probably won't come to the scene.
3) If the accident involves a "hit and run" situation, most car insurance policies require that you inform the police within a specified period of time and to also inform your insurance company. Call your company or broker to check on those details. Otherwise, you may not be covered for the hit and run.
4) Try to get the names and addresses of all the people who were involved in the accident. Also try to obtain their driver's licence numbers and vehicle license plate numbers. These days, having a cell phone will make things much easier as you can simply take photos of plates and licenses. If you can, also take photos of any registration information. Oftentimes, the person driving a car is not necessarily the registered owner of the car.
5) Obtain names, addresses, and phone numbers of any passengers involved and any witnesses to the accident.
6) Make sure to take plenty of photos of the accident scene. Also, take several pictures showing the damage to your car. Make sure the photos you take are from several different angles and distances. Also, try to take photos of all the other vehicles involved in the accident. Sometimes, your car may not look so bad, but that's only part of the story. That's why it's important to take photos of all vehicle involved. Also, take photos of any injuries you might have.
7) Notify your insurance company and/or insurance broker of the accident. Keeping the accident a secret from your company may not be wise as many auto insurance companies require you to report accidents to them. If you don't, you might be in violation of your policy in which case you might be denied coverage should you later decide to make a claim or if a claim is brought against you.
8) If anyone involved in the accident was hurt, or if the damage to your vehicle exceeds $750, you need to notify the DMV within 10 days of the accident. This is done by filing an SR1 form. This form can be downloaded from the DMV website. The more information you have, the easier it will be to fill out the form. Ask your insurance company and/or broker for help if you need assistance.
9) If you are injured, you should get medical attention as soon as possible. Your health and well being are very important. This is not the time to be brave and stoic.
10) Consult with an experienced personal injury attorney if you want to review your legal options.