A lot of these guide books for authors can be heavy going and soul-less, and written by people painfully under qualified to give any sort of advice on how to do it.
Not so with this excellent example of how to write a guide book.
A good guide book should obviously contain lots of useful and practical information, help and professional insight but it's also vital that it's teachings are imparted in an entertaining, engaging and inspiring way and this book does it all.

The advice itself is absolutely invaluable throughout. Everything is covered from character development to plotting, scene and chapter structure to tense and perspective, all with a focus on helping you produce writing of a marketable standard. The information is presented clearly in parts and subsections with useful end of section summaries designed to make navigating the books mine of insight easier (because you will want to refer back to it time after time.)
The section on prose style in itself contains enough jewels to justify purchase but the whole book is rich with advice, points, tips and theories (many of which are clearly demonstrated in practice using excerpts from contemporary and classic published works) which cannot fail to make you a better writer.

I've read this cover to cover with my own work in progress temporarily on pause and already it's improved my style, made my work cleaner and more economic and has even inspired the addition of a fundamental plot element which I didn't see coming and as a result my manuscript is already infinitely better than it was (and that's without even resuming work on it yet.)
I now intend to read it again from front to back with a notebook and pen to hand applying its wealth of knowledge to my work.

I would rate 'How To Write' as highly as Stephen King's 'On Writing' and Walter Mosley's 'This Year You Write Your Novel' as essential purchases for aspiring writers and I cannot praise it more highly than to say that of the three, this one contains the most practical advice on how to make your manuscript better.