see also: LifeDrawing
the differences between man and woman
Lotsa Faces - http://www.fellowhumans.org
Convicted head orthogonal views - http://thnom.tehunlose.com/model_resource/index.html
Surgicat - database of bits and pieces at the Royal College of Surgeons of England
http://www.fineart.sk/
http://www.3d.sk/
http://characterdesigns.com/
http://www.scott-eaton.com/anatomy-for-artists-online-course -I think about taking this one.
http://www.madman.com.au/actions/catalogue.do?method=view&releaseId=6489