This page under construction - some links not yet functional, but all titles available from Amazon.
Shamanism: Archaic Techniques of Ecstasy - Mircea Eliade. This is the best book on the topic I've ever seen. Very scholarly and informative! It's not a how-to book, however. It's written more for historical and anthropological purposes.
ANYTHING by Carlos Castaneda. Seriously, this is good stuff. Although proven to be largely fake, they are presented as true accounts of shamanic sorcery taken by Castaneda with Yaqui indian sorcerer Don Juan Matus. Start in the beginning with his first books and read straight through to his last.
In my opinion, whether or not the stories are true is irrelevant. The fact is that they are still very inspiring and serve as a great source of useful and often workable information.
Books by Carlos Castaneda
The Teachings of Don Carlos- Victor Sanchez. A very good condensation of the essential methods found in the works of Castaneda. The only thing I didn't totally agree with at first was the sorcerer's conception of death. It almost sounded like there was no idea of reincarnation at first. But then I realized that the meaning had more to do with not wasting time here while in the physical realm and making the most of each moment.
The Way of the Shaman- Mike Harner. Supposedly a classic intro on shamanism, but not very informative in a lot of ways.
I'll try to add more legitimate references to shamanism here in the future as I find them (preferably books that are recommended from real native americans). Until then, try to avoid anything by 'Sun Bear' and other fakers (who are usually white people borrowing and changing native practices and then trying to call them 'native' practices while making money etc.). Real shamans don't charge for their services and not all native tribes make use of the same generic set of practices. You just can't mix and match and still call it an authentic native 'practice'.