The advice that I have might not be exactly what you are looking for, but I promise I really am trying to give a helpful suggestion, not a pointless criticism. I would say that if your prof's don't know what a med school LOR looks like, you may want to make sure you 1) get them a very informative outline (which I know you are looking for on here) and be sure they will write you VERY strong letter, or 2) choose prof's who are more familiar with med school LOR's that will write you a good letter.
Just wanted to point out #2 above to make sure you have at least one LOR from someone that is familiar with the process. You just don't want to take the chance that the prof's you have already chosen might not be so great at writing a med school LOR on their first try.
Also, does your school have a pre-med committee? There is usually a process that pre-med committees go through to interview their pre-med students and write a letter on their behalf (depending on how the interview goes/how well they know you). Look into this....it is much more valuable for med schools to hear that the University of X endorses you as a future doctor rather than some professor who could be your uncle with a different last name, for all they know.
In any situation, it is always a good idea to blatantly ask a professor to write you a strong letter, if they feel comfortable doing so. You'd rather them be honest with you than just say yes and turn in a generic letter.
