I found the introduction especially useful as it points out the emergence and identification of Zen cults, and contrasts them to the simplest practice of Zen.

The body of the book is in convenient 1 to 3 page short reads. The presentation is in a conversational prose. Common errors are addressed. After tripping over one section (Emancipation), I started reading it in parallel with Huang Po's commentary of the Diamond Sutra, which must be read very very slowly, (without missing the meaning of a single word), and doing this helped me. However, most of the passages are very down-to-earth.

I can't say this is an "advanced" book. There is no "beginner" and "advanced" -- jump in wherever you like. This book is as good a place as any. I also recommend Huang Po, as he also gets immediately to the root and avoids common misconceptions.

The 'grandmotherly kindness' of Foyan, a 12th Cent. Chinese Grand Master of Zen, comes through in this offering from Mr. Thomas Cleary, who's said to be one of the most respected translators in the field. He gets my vote! Mr. Cleary's selection of this text seems suited to our time in that it's from a Grand Master who '...was completely free of any desire for fame or followers and made no attempt to recruit disciples.' Accordingly, his is a 'take no prisoners' style (a complaint in another review) which, naturally, leads to a strong emphasis on self-reliance and (a most interesting kind of) practical advice. I say Refreshing!

'If you want to clarify this matter, you must arouse wonder and look into it. If you wonder deeply about this matter, transcendental knowledge will become manifest. Why? The task of the journey just requires the sense of doubt to cease. If you do not actively wonder, how can the sense of doubt cease?'
(pg. 54)