"Hands of Light" by Barbara Brennan is by far the most powerful book that I have gotten my hands on.
I have found the graphics to be very helpful. Each time I channel Reiki energy on someone, I have been able to go to this book afterwards to find an explanation of what is floating in the aura. It also reassures me that it is not my imagination running wild.
It is a very technical book that requires reading several times over to fully absorb as well as a lot of volunteers to work on.
The pendulum chapter is very detailed with excellent drawings.
