Won't teach you how to write, but it may serve to heighten your awareness of techniques that can be employed to bring credibility to a piece of work. I particularly liked points in the books where she highlights differences between clichéd language and more original language, and emphasises the importance of word economy: how to say only what needs to be said.
I found certain chapters - `Close Reading', `Words', `Narration', `Character', `Dialogue' and `Gesture' - both interesting and informative, and I believe they considerably sharpen the tools needed to critically analyse other's work if we are to improve our own writing and yet avoid overt imitation or, worse, plagiarism.
You do, however, get the impression in two of those interesting and informative chapters - `Character' and `Dialogue' - that, although very good points are made, much of what is included is unnecessary: too often much of these chapters seem to merely serve to summarise lengthy sections of stories she particularly likes, but not provide anything more to a valid point that was made succinctly enough in one or two paragraphs. I wish to avoid being too critical here, though, as the points in these chapters are generally well-made and maybe the length of some of the examples used here is necessary for emphasis; to avoid these points being neglected as incidental digressions.
Here, though, I must mention the two chapters - `Sentences' and `Paragraphs' - that I believe are essentially pointless as they are too analytical of specific examples and bring out little in general that a practising writer may use to inspire their own technique. I would also go as far as to say that where good points are made - in `Sentences' - the examples used to highlight these are not particularly good and, in some cases, serve more to contradict than to clarify. In addition, coming as do so early in the book - chapters one and two - is fairly off-putting and could deter you from wishing to read further, which would be a shame as there is much here for a close and critical reader to consider when approaching their own reading and writing.
And that would be the book in a nutshell: yes, there is a lot to be had from it and is, therefore, worth recommending for that, but there will be the occasional section where you may ask yourself why you are bothering.
All-in-all though, worth the time and effort.