"Dr Google" will make you think that your mild cough is actually cancer, but MedNexus wants to change that. It's a medical search site, but instead of just matching popular sources, you get information that's vetted and useful, from published studies to trustworthy articles on virtually any health topic. The service looks deceptively simple: just type in what you're looking to learn about and it will spit back some results. Those results are the clincher though -- they're broken up into groups, including a detailed explanation of the condition you searched for on the left side and links to more reading on prevention, treatment, management and risk factors for the disease. The actual "search results" are broken up into three categories: "health topics", or trustworthy, vetted articles from verifiable sources; published research from scientific and medical journals; and then at the bottom, "forum posts" from health related user communities around the web.
All in all, it's no substitute for actually talking to a doctor, but it's much better than you could do by just googling symptoms and hoping what you find is useful or relevant. Hit the link below to give it a try.