Meet with the client and gather the basic facts
A lawyer needs to understand what it is you think went wrong and why. As someone who evaluates dozens of cases a month, I can say with some certainty that time lines and written summaries are greatly appreciated. Knowing what the client thinks went wrong provides the starting point by telling the lawyer which records he needs to gather and for what period of time. It will also help him understand what damages the client has sustained. Finally, it will allow the lawyer to make at least an initial evaluation about what kind of impact this potential plaintiff will have on a jury. Lawyers know that no matter how good the facts of your case are, the value of your cases is zero unless a jury will want to give you money at the end of the trial. Recognize that you are being evaluated as a potential client and witness at the same time that you are meeting with your new lawyer.
Gather the records necessary for review
Just learning what the client remembers isn't enough--a lawyer has to actually gather a client's medical records to evaluate his/her case. This usually means the entire chart, not just the part that seems to the client to be relevant. A med mal case is a big undertaking for any lawyer, one that will involves hundreds of hours of work and tens or hundreds of thousands of dollars in expense expenditures. The lawyer wants to be sure that she has looked under every rock to make sure that there is nothing that will derail an otherwise good case, and the start of this process is to get complete copies of all of the records (and, if your case involves imaging studies like x-rays, CT scans, MRIs and other similar studies, copies of those films too).
Have the records reviewed by an expert to see if there is malpractice
A malpractice case won't succeed without at least one good expert to testify for you. Your lawyer will try to look for such an expert right now, at the outset of a case. Sometimes your lawyer will tell you who he is talking to, sometimes he won't. He's usually following the wishes of his expert here, because there are some experts who don't want to receive calls from clients after they have told the lawyer that there's no case. Some lawyers use physicians who they know and have worked with, others use services who have a collection of doctors who have agreed to look at cases. The expert generally has to be from the same area of specialty as the doctor who is the potential defendant. Either way, the expert is trying to decide whether she thinks that the care that was rendered "deviated from the accepted standard of care". Basically, the expert is trying to decide whether the target health care provider made a significant mistake, either by doing or not doing something.
Have the records reviewed by an expert to see if there is causation
Even if the expert thinks that the doctor made a mistake, this is usually not enough. Most (and maybe all) states require that the patient prove that the mistake which the doctor made actually harm the patient. This means that if the outcome would have been the same even if the patient had gotten good care, there is no case. An example would be a short delay in diagnosing advanced cancer. If the expert believes that the a patient's treatment and/or chance for a cure wouldn't have been any different if the cancer had been discovered when it should have, this is not a case lawyers will take.
Make an initial assessment of value
Your lawyer will try to get a preliminary idea of the value of your case. He will rarely share this with you because it's so early in the case and the chance that he'll be wrong is too great. Nevertheless, this is an important step in the process. These cases are so expensive and time intensive that lawyers want to have some idea whether a.) they'll get well for the hard work ahead, and b.) you'll be left with a reasonable recovery. Because almost all med mal cases are handled on a contingency fee basis (meaning that the lawyer will be paid by retaining a percentage of whatever you recover), the size of the lawyer's fee will depend on the value of the case. The sad truth is that there are no good small value med mal cases. Even on a one expert case, the costs can be $50,000. If the case value is $150,000 and the contingency fee is 1/3, that means that the client only ends up with $50K. For many of us, any case where the lawyer ends up with more than the client is a no take case
Tell the client
This is probably the part that confuses most clients. Even though most lawyers have done these steps, they often don't tell the client what they've learned. In part, this is because it's hard to tell a family who is convinced that their loved one died because a doctor made a mistake that they're wrong. In part, it's because some lawyer don't want to take the time to try to explain the nuances of the process to the family. Many times, a client will receive a letter from the lawyer months after having met with him or her which simply says that the lawyer isn't interested in representing them without further explanation. If you get one of these letters, know that you're entitled to a better explanation and seek one out. Realize, too, that this entire process takes months. If you come in with 60 days to go before the statute expires, most lawyers won't even look at what you have.