Just thought I'd share one of my favorite talks about mushrooms, I :
Presentation by Paul Kroeger at the 2012 Vancouver Mushroom show by the Vancouver Mycological Society.
The talk (with accompanying slides) is over an hour long and discusses the history and modern use of psilocybin mushrooms, as well as an overview of several common species of psilocybin mushrooms, their habitat, etc.
Kroeger is a great speaker as well, obviously passionate and knowledgeable about mushrooms.
There's a little bit of humor, and plenty of anekdotes to keep things entertaining and interesting.
Give it a watch if you're interested, you won't regret it
"The only way to deal with an unfree world is to become so absolutely free that your very existence is an act of rebellion." - Albert Camus