"Scrying for Beginners" by Donald Tyson is an extremely comprehensive and readable introduction to scrying for the beginner, but the book's wide ranging scope detailing scrying with crystal balls, mirrors, water, oils and dowsing, plus it's very thorough history of the art, makes it a very good buy for the more experienced scryer. Tyson writes in a very straightforward and uncomplicated style so the book is a satisfying read. Of particular interest to me was his section on crystal ball scrying, and I enjoyed his exposition of the method of Dr. John Dee and found this part of the book very enlightening. Tyson details numerous other methods of scrying and he deals with each of these in the same clear and informative style he uses throughout the book. I think this book will be very useful for the beginner, however more advanced scryers will, I'm sure, really enjoy his very detailed histories of scrying techniques from ancient Babylonia and Egypt right up to Nostradamus and the modern day.