CIEF - Consortium for Improvement in Erectile Function
Group of health care professionals informs about impotence and treatment options. Answers to supplied reader questions.
http://erectilefunction.org/

eMedicine Health
Information on erectile dysfunction, written by health care professionals for patients.
http://www.emedicinehealth.com/articles/43032-1.asp

Men's Sexual Problems Center at SeekWellness
This site, written by Dr. Chris Steidle, covers male sexual dysfunctions including impotence, premature ejaculation, and Peyronie's Disease and offers general information about penile anatomy, physiology, physical exams, various treatments, and how to find a specialist.
http://www.seekwellness.com/mensexuality/index.htm

Health Central - Erectile Dysfunction
Detailed information on erection problems and their treatment options. Videos and advice from physicians.
http://www.healthcentral.com/erectile-dysfunction/?ic=1102

eMedTV Erectile Dysfunction Channel
Providing medically reviewed information on the incidence, symptoms, types, and current treatments.
http://erectile-dysfunction.emedtv.com/

Impotence - MedicineNet
Multi-part article explaining the causes and possible treatments of impotence.
http://www.medicinenet.com/script/main/art.asp?subject=impotence_ed