A good place to start is Medline Plus. Medline Plus is a website compiled by the National Institutes of Health and the National Library of Medicine, and their trusted resources (like the CDC and the National Cancer Institute). In addition to basic medical information, they also feature videos, articles, links to other health organizations, health check tools, and even a link to clinical trial information.
Medline Plus can get you started, with links to even more information with the latest news. And, checking this out might help when you review your insurance this year – including getting signed up through the Affordable Care Act starting on November 1.