First of all, this is not a "course" in meditation. It does not guide you step by step, systematically. It is basically a collection of texts on Meditation & enlightenment, all of them very good. Thomas Cleary does a good job of translating (although something seems amiss about the translation of Dogen), and the notes are very helpful. This is a good book to see how much or little meditation has changed. The talks by Man-an are particularly insightful. I would recommend this book to anyone studying the Zen texts of old, but if you want to know how to meditate and need very basic instructions, go elsewhere. This has alot of obtruse explanations & metaphysics that may confuse you if you haven't studied much Zen before.
For those of you who are perceptive, should you buy this book, you will see that it is packed with wisdom. Of course, a familiar background with Zen would be helpful in understanding the book. However, even if you don't have any familiarity with zen at all, Cleary has provided notes at the end of the book to help give more depth and interpretation to the texts. These short discourses are the "real thing" when it comes to zen literature. The content of the each discourse deals with meditation and possible pitfalls to avoid. Also it is clear that meditation practice should be carried through one's everyday life, on the cushion and off. A primer of Soto Zen meditation also known as the "non-doing" method is given as well as other methods that are more concentrative in nature. I would say that this book is intended for practitioners of Zen and less so for investigative scholars.