Here is a spiritual practice uncomplicated enough for anyone to learn, yet rich enough to be worked with for a lifetime. The traditional Chan (Chinese Zen) practice called Silent Illumination begins with nothing more than putting aside all thoughts except the awareness of oneself “just sitting.” It’s so simple in execution that it has sometimes been called the “method of no-method”—yet simple as it is, the practice is subtle and profound, with the potential for ever subtler refinements as the practitioner moves toward mastery of it. When fully penetrated, this radical form of emptying one’s busy mind-stream leads to perception of the vast ocean of pure awareness.
Zen dharma talks, even those given on retreat, just don't transcribe well into book form. The only thing drier than transcriptions of Zen dharma talks is Zen commentary. If you are a Zen practitioner you may love this book. As a Therevada Buddhist trying to understand Zen a bit better, this book was like a mouthful of sand to a dehydrated man.
The best, clearest handbook on Zen practice that I've found. Watts and Suzuki may make for better introductions, but this collection of short lectures is refreshingly clear & precise.