This book is a collection of aphorisms, fighting know-how and philosophical insights that was compiled after Bruce Lee's untimely death in 1973, from work towards a book he was never to finish.
Considering the fact that it was not fully completed, it is remarkably coherent, and organised into sections covering literally every single area of combat. It is not specifically a book about Kung Fu - it contains grappling techniques from Judo and Ju-Jitsu, along with a great many techniques taken from western Boxing.
For the experienced martial artist, it will provide many dynamic and helpful points, and for the beginner, it will help to illustrate the enormous depth and fascination that the subject holds for so many people. For both beginner and expert alike, it will bring a clearer understanding of what Bruce Lee empasised in his martial art, what he calls Jeet Kune Do: the fluid reality of physical violence. Because of this, it is a revolutionary book, and because of this, simply to read it will make you a better martial artist, even only if it leaves you feeling humbled at the depth of Lee's intuition and brilliance, and inspires you to work harder.
Regardless of the martial style of the individual reader, this book is a work of unremitting genius. Buy it. Read it. Understand.