Extremely well laid out, this iconic book is valuable to get a birds-eye view about the Children's Book market and personal remarks from some of its known publishers and agents. (I really enjoyed these "Q&A" interviews with editors, author suggestions and other 'side-bars'.) Still, this book is what I would call a 'scaffolding tool'. I mean, you have to read this book with an attentive spirit, take a lot of the information seriously, but then RESEARCH more. AND do not take all items stated as 'Bible'. As a reference book, it's already aging!
For example, there is a superb section "Book Publishers". Most publishers are listed. With each listing is the address & webpage, acquisition team info' (editors, etc.), the type of books they publish, how to contact them and other information. However, a writer intended to be published, must go to each website, cross reference and update the information you find.
I bought this book in 8/2009 (mind you this IS a 2010 reference) and in my own efforts, looking at each publisher's web site, I found enough info' in the "Book Publishers" section to be 'incorrect'. Of course this makes sense...the book was likely written and finalized at the beginning of this year!
Keep in mind, the market is fluid, editors change jobs, companies are tightening their acquisition preferences and some have very, very clear specifics relative to how and what to submit and most importantly, even if you should submit a manuscript(Seriously, some even tell you their preferred envelope type. FOLLOW their directions to a 't').
Do you homework! Good luck!