Blonz Guide - First Stops
Medline Plus - Top knotch resource for health information, includes a health encyclopedia and searchable links for drugs and supplements
Memorial Sloan-Kettering Cancer Center - Quality science-based review of herbal products, complete with references.
Medscape: - Excellent site focused on the practice of medicine, and the industries relating to that practice.
Berkeley Wellness Letter - Reliable Information on health related issues
Mayo Clinic - Good for mainstream questions, reliable but limited resources on alternative medicine
WebMD - News Articles, presents cutting edge possibilities, but unclear what you should do about it. Be careful with advertisements. They are linked to key words in the articles. Their presence does NOT indicate any endorsement but they might lure the curious toward unsubstantiated product use.
HealthLine: Searchable references & learning centers.
Government Clearinghouses: Conservative, reliable, but not cutting edge