That's wiki's description. Its doesn't go over much though. I guess I expected more people to know about this wonderful area of the internet.
I think one of the more interesting things I stumbled apon was a series of pdfs for the establishment and manufacturing of a retail methamphetamine laboratory. And not some shitty guide, it went over the actual chemistry, the actual lab equipment and explanations on making your own pre cursors so you don't have to get dea watched chemicals like sudo.