Diseases

Centers for Disease Control and Prevention
http://www.cdc.gov/ncidod/diseases/index.htm

Medline Plus
http://www.medlineplus.gov/

Merck Source
http://www.mercksource.com/pp/us/cns/cns_home.jsp

Healthy NJ
http://www.healthynj.org/dis-con/diseasesconditions.html