http://www.niddk.nih.gov/health/urolog/summary/prstitis/prstitis.htm
There are brief explanations of the four types of prostatitis at this site developed by the National Kidney and Urologic Diseases Information Clearinghouse.

http://www.prostate.org/science.html
This location provides some current scientific research into the causes and treatment of prostatitis. There are several articles on bacterial causes and potential remedies.

http://text.nlm.nih.gov/nih/cdc/www/91txt.html
Erectile dysfunction used to be called impotence. This consensus statement from the NIH presents facts related to frequency, causes, and treatments.

http://imsdd.meb.uni-bonn.de/cancernet/201121.html
It might make you uncomfortable to think about it but if you are a guy but you need to check out your scrotum for cancer. You might be able to catch it before it gets even more serious. The condition is usually curable in the early stages.

http://www.herpesweb.net/general/menupage/general_info.htm
Nobody want to talk about genital herpes. Nevertheless, it is a serious problem for those that have it. Check out this site to get information in an easy to understand way.

http://www.niaid.nih.gov/factsheets/stdhpv.htm
Genital warts are caused by human papillomavirus. There are more than 60 strains of this virus, some of which may cause cervical and other genital cancers (including cancer of the penis). Only about half of all women surveyed who came up positive for these viruses actually showed symptoms.

http://www.ama-assn.org/insight/gen_hlth/atlas/newatlas/male.htm
This is a sagittal section illustrating human male reproductive anatomy in color. The site is sponsored by the American Medical Association.