Circlist (a pro-circumcision advocacy group)
http://www.circlist.com
Erection Photos
http://www.erectionphotos.com
Guttmacher Institute: In Their Own Right: Addressing the Sexual and Reproductive Health Needs of Men Worldwide
http://www.guttmacher.org/pubs/itor.html
National Cancer Institute (extensive sections on prostate and testicular cancer)
http://www.cancer.gov
National Organization of Circumcision Information Resource Centers (NOCIRC) (an anti-circumcision advocacy group) Some of the statements on this site, such as that circumcision reduces the length and erotic sensitivity of the penis, are poorly documented.)
http://www.nocirc.org
The Naturist Society
http://www.naturistsociety.com
Prostate Cancer Foundation
http://www.prostatecancerfoundation.org
Prostatitis Foundation
http://www.prostatitis.org
University of Delaware Mammalian Histology: Male Reproductive System (microscopic anatomy)
http://www.udel.edu/Biology/Wags/histopage/colorpage/cmr/cmr.htm
