It has been said that if magick is the ability to make desired changes, then the most powerful form of magick is the ability to change your mind.
I'm not sure that's completely accurate, but the ability to fully use the mind to make desired changes is certainly quite powerful. To my mind, no tool is better for changing the mind than hypnosis. Llewellyn publishes many books that include hypnosis as well as some very good ones that focus on hypnosis including:
Hypnosis for Beginners
New Age Hypnosis
Self-Hypnosis for a Better Life
Self-Empowerment Through Self-Hypnosis and
Self-Empowerment Through Self-Hypnosis CD Companion
But why is hypnosis and self-hypnosis so effective?