An illustrated history of this practice, types of prayer wheels, how to use them, and a teaching by Lama Zopa Rinpoche.
http://www.dharma-haven.org/tibetan/prayer-wheel.htm
Texts that discuss various forms of Tibetan Buddhist meditation. Includes segments on Dzogchen, Niguma on Mahamudra, and Milarepa.
http://www.anu.edu.au/asianstudies/buddhism/tib.html
Information about deities of the Vajrayana pantheon taken from "The Tibetan Book of the Dead" and other sources. Includes meditative poetry. Author: J. Denosky.
http://www.buddhanature.com