National Center for Complementary and Alternative Medicine: This website from a branch of the NIH provides summaries of specific supplements, acupuncture, homeopathy, and many other CAM topics. 

NIH Office of Dietary Supplements: This website includes a general discussion of supplements and provides fact sheets for specific supplements.

Complementary and Integrative Medicine Summary, MD Anderson: Reviews of complementary and integrative medicine approaches for cancer provided by MD Anderson staff.  This impressive site offers discussions and even scientific reviews of everything from ayurvedic and traditional Chinese medicines to nutrition and diet to acupuncture and energy therapies. 

Memorial Sloan Kettering Herbal and Boatnical Remedies Page: From the Memorial Sloan Kettering website, this section includes discussion of an array of herbal medications, including a clinical summary of how these agents have been used, anticipated side effects, proposed mechanism of action, and references, along with a summary of utility for multiple agents commonly considered as CAM anticancer therapies.

American Cancer Society Section on Complementary Medicine: ACS offers a very comprehensive website that includes discussion of mind-body-spirit interactions, massage and acupuncture, herbal remedies,diet and nutrition, as well as other proposed CAM anticancer approaches.  Many of these topics include rather extensive discussions of the evidence and the limitations of this work, along with references.

Cancerguide.org Alternative Medicine information: Created by a longtime cancer survivor named Steve Dunn, Cancerguide.org compiled his reviews of several alternative medicines, diets, and other CAM approaches.  Not as comprehensive as some of the sites listed above, but a personal discussion based on thoughtful reviews. 

Consumer Lab: Evaluates the quality of dietary supplement and herbal products.  Subscription required to read reviews.

QuackWatch: A member of Consumer Federation of America, Quackwatch is a nonprofit corporation whose purpose is to combat health-related frauds, myths, fads and fallacies.