Centers for Disease Control http://www.cdc.gov/
National Institute of Health http://www.nih.gov/
NYS Health http://www.nyhealth.gov/diseases/
eMedicineHealth http://www.emedicinehealth.com/script/main/hp.asp
Medicine Net.com http://www.medicinenet.com/diseases_and_conditions/article.htm
Medicine Plus http://www.nlm.nih.gov/medlineplus/healthtopics.html
Your complete family medical quide http://www.health-disease.org/
Discovery Health Encyclopedia http://health.discovery.com/encyclopedias/encyclopedias.html