Sometimes there is too much information on the internet and sorting out the crazy from the really crazy is tricky. Fortunately when it comes to health and nutrition the government itself actually has some pretty good websites and information. You are probably familiar with the NIH and CDC websites but the Nutrition.gov website is pretty good too and is a good source for information on botanical and herbal supplements and medicines Nutrition.gov is produced by the National Agricultural Library, part of USDA.
You can read more about gymnosperm derived compounds such as Ephedra and Ginkgo and numerous other herbal supplements and remedies.
You can download all the factsheets at once in pdf format if you click the image above. If you know someone who is a little too into herbal remedies you may want to pass on a copy. Not because the herbs are necessarily bad or dangerous but because they may have adverse interactions with other commonly prescribed medicines (eg for diabetes or blood pressure) and the factsheets clearly summarize our current state of knowledge.