This is a great guideline book published by the American Academy of Family Physicians and is updated every year.
It has everything we need to know about the match process including timeline, ERAS, NRMP, and all the details about how to apply for residencies and fellowships.
The book is available for free from the AAFP website.
I attached a PDF copy of the current 2010-2011 edition to this post.
Must read