This is probably the best guide to document formatting I've seen yet. Of course, half the staff at Writers Digest magazine wrote it! Most of them are writers or editors as well, so it only makes sense that it would be good.
I looked at several different formatting books in my search for the best. Many of them got great reviews when they were released. The problem is, most of them are more than 5 years old. With the publishing business changing as rapidly as anything else these days, you need an updated resource to follow, especially if you are new to the business of writing - and yes, it is a business. In business, things are expected to be done a certain way, and this book shows you that way.
This book is chock full of full page examples of everything from proposals, cover letters, tables of contents, etc. It's broken down into sections like most of the other books, each one covering a topic such as articles, novels, and screenplays.
If you want a book that is easy to follow when formatting your manuscript and writing the associated correspondence to an editor/publisher/agent, this is the book for you. The example documents even show you how many spaces to leave between lines etc. I don't think they could have made it any easier if they had sent someone to my house and had them walk me through the formatting!
One thing I thought disappointing was mentioned by another reviewer. Personal essays is mentioned on the cover, but after a quick search, I wasn't able to find that topic covered at all in the book, even in the index. My guess is that it's assumed that these documents would be handled according to guidelines from a different section, although which section eludes me.
Overall, this is the best book out there. It's new, and covers the currently accepted formats for a plethora of documentation. If you're searching for a book like this, spend the money, it's well worth it.