I love this book. It's written by the founder of Nanowrimo, and is more about completing 50,000 words in one month than anything about writing a novel, i.e. voice, point of view, characterization etc...
Still, that being said, from having done the 1 month novel, I realize that just sitting down and writing has more to do with writing than any of those other things, and in the end, that makes this a fantastic book for writers.
I love the humor of this book - Baty is a real wit, which makes it fun to read. He has tons of ideas from various nanowrimo participants, many of whom have written published novels, as well as great section on how to edit your novel, and something from publishers etc.
You have to know going in that it isn't really about the mechanics of writing, and when you do, you will find it exactly what you need to get that novel finished.
My only regret with this is that I bought it after starting Nanowrimo and only had the time to read it once I was finished my 50,000 word 1st draft. When reading it after, I felt that my novel could have been a lot better if I'd read this first.