I am always blown away by the wisdom, kindness, and helpfulness of CDbaby. They are the site I sell my CD's and downloads through, and their artist resources end is just TOP NOTCH. And you don't have to be a member or sell through them to access it:
diymusician.cdbaby.com
My favorite page on this is "Derek's Advice". This is a goldmine from Derek Sivers, the founder and CEO of CDbaby. This is grass-roots-meets-professionalism-and-success at its best. Endlessly useful and down-to-earth