I think it would be a good idea to compile a list of reference sites for human anatomy, proportions, and all the like! If you have anything you'd like to share, just paste your links in the comments and I will add them to the list.
INTERNET RESOURCES:
Posemaniacs.com - http://www.posemaniacs.com/
Great website with hundreds of rendered male and female bodies in all varieties of poses.
How to draw the head from any angle - http://www.stanprokopenko.com/blog/2009/05/draw-head-any-angle/
Interesting and simple guide on how to draw a proportionate head from any angle.
Male body hair guide - http://www.heromachine.com/blog/wp-content/uploads/2