Plot55.com 
Provides information on the cultivation, preparation and use of entheogenic, hallucinogenic and psychoactive plants.
http://www.plot55.comWasiwaska
Center of studies for ayahuasca, the sacred brew of Amazonian shamans. Includes information about the center, and their seminars and presenters. Located in Brazil.
http://www.wasiwaska.org
Council on Spiritual Practices - Entheogens
The purpose of the Entheogen Project is to systematically gather knowledge about the immediate and long-term effects of entheogen use. Includes essays and an annotated list of topical books.
http://www.csp.org/practices/entheogens/entheogens.html
The Mad Hatter
Guide to entheogen use; includes essays and information on drug laws and suppliers.
http://www.clearwhitelight.org/hatter/
A Brief History of Peyote
The divine cactus in historical context.
http://www.peyote.org/
Entheogen Dot
Online community, and an information resource with a focus on shamanic plants.
http://www.entheogen.com/
Peyote51
Features information on the history and chemistry of this plant, and links to related sites. Also offers for sale peyote cacti.
http://www.peyote51.com/
