The following is a list of associations and organizations dedicated to providing invaluable information and resources concerning  the treatment impotence (Erectile dysfunction):

American Diabetes Association (ADA)
The ADA offers many free publications for people with diabetes, including several brochures and articles on men's sexual health.

www.diabetes.org.

American Association of Clinical Endocrinologist
This site is furnished by the Association and the American College of Endocrinology.  They present clinical guidelines for the treatment of endocrine conditions including male sexual dysfunction.

www.aace.com

Mayo Health Information
This is an educational site provided by the Mayo Clinic.  The site includes articles, reports and case studies concerning impotence.

www.mayohealth.org