One handy reference source that I rediscovered this summer was the website Erowid, which is a non-profit, donor and grant supported reference site that covers all aspects of psychoactive materials. Not all of the information provided is simply a matter of scientific fact, although it does have the available scientific facts, but the statements available are largely compilations of the insights and opinions of others, so that people interested in knowing about psychoactive drugs, be they in law enforcement, experimenting users, or policy makers, can start from the same page in terms of what basic reference sources have said about the issues.
In addition to its more slowly updated reference oriented materials, the site also has mechanisms that allow for new user generated information to be quickly generated with the caveat that it is user generated information. Thus, it performs the public service of helping to identify, for example, potential outbreaks of problems in the unregulated illegal drug markets that could pose a public health risk.
It is a good first stop for anyone wanting to gather up basic information about a variety of psychoactive materials before getting sucked into a search routine that will obscure important voices in any part of the discussion.