MedlinePlus is one of the best places to start doing consumer health research. The content is curated and regularly updated by the U.S. National Library of Medicine.
General home page for information on consumer health, medical publications, research, and clinical trials. Note that ongoing research and trials are not considered settled sources of information but only preliminary sources of information.
Many of these resources and programs are funded under the provisions of the Library Services and Technology Act from the Institute of Museum and Library Services.