Ah, he says Einstein is religious. I don't think that's true, is it? But, that little smudge aside, this book is, as has been said before, one of the best introductions to Ch'an buddhism you can buy. It outlines the major forms of zen practice, some you probably hadn't heard of (HuaTou, MoChao), as well as some autobiographical parts, explanations of core Buddhist belief, as well as a great chapter on compassion. In fact, the book gives an exercise in compassion you can practice each day to help you out with it. You don't find that much in Zen these days.
I have studied Buddhism for over 20 years (mostly Zen), but was not all that familiar with authentic Ch'an Buddhism. Master Sheng yen was recommended by a friend and out of all his books I've found this the most accessible and most comprehensive. It's a great place to start if , like me, you want profound wisdom at an understandable level.