professionalmedicaljobinterviews.com

Recommendation letters are sort of an appraisal of your performance during your last employment usually prepared upon request from your bosses. These may be of some value for such a specialized industry as the medical field for having experience and your boss stating that is a good thing. It may or may not influence your ability to land the job but it can surely reflect your work ethics and skills.
The resume usually has references listed in them which are previous bosses that can attest to the contents of your resume and your past experience. Be sure to inform these people that you would be placing them as such references so they are aware and will expect the call, not brushing it off as a prank. Be courteous enough to thank them at the least should you hear they have been contacted and you got the job.