If the subject interests you then this book is quite good. It approaches the subject of Out of Body Experiences with scientific scrutiny which adds a level of credibility to it. Nevertheless because such Experiences can’t be independently verified we have to trust that the author has been entirely honest—which,in my opinion, he seems to have been.
Much of what he says is similar to my own limited Experiences in this realm. I too have experienced the vibrations before seeming to leave the body. Since this book is rather old, that would also lend credibility to it, since I doubt that the vibrations accompanying OBEs was were well known at that time.