The first thing you need to do is seek medical care; your family doctor is a good start. Next, all facts (accident reports, witness statements, photographs of the cars, etc.) need to be gathered and your medical records requested. After your medical treatment has ended, you and your attorney will develop a settlement strategy and attempt to settle your case with the insurance company. Your attorney will help you analyze the insurance company's best offer and compare it to what you might get by going to trial. Of course, you must know that every case (even “obvious" cases) can be lost.
Sometimes, attempting to settle with the insurance company before filing suit is not a worthwhile pursuit. Insurance companies are notorious for using pre-suit negotiation to find out as much about you, your lawyer and your doctor as they can, and then make a lowball offer.
It is a dangerous practice to wait until the statute of limitations has almost expired to file suit. While there are legitimate reasons to delay filing suit, there is no excuse to wait until the last moment just to see if the insurance company will settle your case.
Once the lawsuit is filed, both sides engage in a legal process called discovery. Each party is allowed to investigate what the other side is going to say at trial. The defendant will be permitted to access your medical and work history, including your income records. You may have to give a deposition under oath or submit to a medical examination by a physician of the defendant's choosing. The defendant is also subject to discovery. He will answer written and oral questions about his own background, and give sworn testimony about the incident at issue.