http://www.cdc.gov/nchstp/dstd/personal_Health_Questions.htm
National Center for HIV, STD, and TB Prevention, Centers for Disease Control and Prevention
This page links to fact sheets for a variety of sexually transmitted diseases, including bacterial vaginosis, chlamydia, HIV/AIDS, human papillomavirus, gonorrhea, herpes, pelvic inflammatory diseases, syphilis, and trichomoniasis.