I found this great directory of healing herbs, vitamins and homeopathic remedies which links them to particular health conditions.
It's a part of the PCC Natural Markets Website. This is a health food store chain in Washington state. My guess is that it's some syndicated content from somewhere, but it really is comprehensive. I mean, Wow!
I guess what blows me away is how many studies and articles they cite for each condition and/or remedy. It's dozens! For insomnia, there are 41 articles and peer-reviewed journal entries listed. For arthritis, 114 listed! I had no idea there was such a complete resource available for us online, for free! How friggin' cool...
Here's the link. Take a look. Pick a health condition, and see what natural remedies apply. Or, pick a remedy, and see what conditions it's helpful for.
Our favorite local health food store in Westerville, Raisin Rack, has a similar listing, syndicated from a different source. It's good too.
And if you want a directory that has herbs and drugs, and that focuses a lot on herb-drug interactions, DrugDigest is for you.
I have no idea of the authority of these Websites, but my impression is that they are very good. Well laid out, easy to navigate, and not overly biased towards Western medicine as the "only way to go" like WebMD.