If you have been injured in the accident, make sure to call 911 or have someone call 911 for you. The most important thing after an accident is to make sure that you are safe and not at risk for further injury. If you are still in your car, only move if you are not feeling lightheaded or feeling any pain. If you are able to, get as many details about the other party as possible such as their name, insurance information, contact information, as well as other important pieces of information. See here for more details on how to go about doing this.
Again, if you are able to without risking further injury, take pictures of the scene of the accident as well as of any injuries to you, your passengers, or damages done to your vehicle. Accident scenes are cleaned up fairly quickly once the police arrive so this is your only opportunity to document this information before everything has been cleaned. If there are witnesses to the accident, ask them for their contact information as they can be very helpful to your case later on.
At the time of the accident avoid making any comments that might place the blame on you. Stick to the facts of what happened and let the responding officer determine if there is any fault.
If you feel you have sustained injuries following your accident it is probably in your best interest to seek legal representation to make sure you get the compensation you deserve. Contact me for the help you need.