www.nationaleatingdisorders.org (go to Links & Resources on the right)

Body Image And Health Task Force
www.hec.osu.edu/bitf/index.htm
(there's a link to Muscle Dysmorphia in the menu on the left. And there are more links about Muscle Dysmorphia from that page)

www.mirror-mirror.org (they have an "eating disorders' at the bottom, and then there are a bunch of more individualized links, even
'athletes')

www.something-fishy.org

www.edreferral.com (this is for professional treatment)

www.withjess.com

www.doilookfatthemovie.com
A documentary on gay men, body image, and eating disorders

National Eating Disorder Information Centre (Canada) www.nedic.ca

I personally recommend The Adonis Complex by Harrison Pope. It's an excellent book on males and these issues. Also Making Weight by Arnold Andersen, Leigh Cohn, and Thomas Holbrook.