I was very skeptical about hypnosis until a friend demonstrated it to me. Now hypnosis is my tool of choice for self-improvement, and this book is considered the best overview / basic course for those who want to learn it. Note: this is not about how to embarrass people on a stage, but rather how to use hypnosis to improve your life and the lives of others in consensual situations. The book was a very smooth read, really pleasant for a non-fictional book.
As a follow-up, my friend recommended "The Art of Hypnotherapy" by the same author and a collection of tried-and-true hypnosis scripts which you can find basically anywhere.