I reference From Inspiration to Publication: How to Succeed as a Children's Writer: Advice from 15 Award Winning Writers quite often. It contains fifteen chapters (all from different award winning children's writers on topics such as determining your readership age, developing your characters, plotting a great story, maintaining point of view, bringing non-fiction to life for young readers, and more. If I'm stuck in my children's writing, From Inspiration to Publication is usually where I turn.
Best of the Children's Market (A Collection of Over 80 Articles and Stories Published By Leading Children's Magazines) is another one of my favorites. Not only does it contain instructional articles to help writers develop their craft, but it also contains examples that have actually been published by children's magazines across the country. There are also examples of stories from all age groups and reading levels, as well as all religious and cultural backgrounds.
The 2011 Children's Writer's And Illustrator's Market is a bible to children's writers. Containing updated information about magazine and books markets around the world, this book is a great guide to what particular publishers are looking for more of, what they do not accept, how they want submissions to be sent, what their basic payment terms are, and who to address a cover letter or queries to.
Essentials of English: A Practical Handbook Covering All the Rules of English Grammar and Writing Style (Barron's Essentials of English) may seem like a incredible boring book to recommend, but I'm a nerd so I'm doing it. I love this book and turn to it's pages when I have a grammar, tone, or word usage question.
My last favorite book about writing is not exactly a book I can give you an Amazon link for. My other book is The Instruction Manual for the Institute in Children's Literature class that you can find more information about here: http://www.institutechildrenslit.com/ I took their "Writing for Children and Teenagers" course under Daphne Hogstrom (author of What Will We See?, one of my favorite books as a child). I highly recommend it! It gives you a chance to have a published children's author look over your work and make suggestions on how to improve your craft. You should definitely check it out!
What are your favorite books on writing and why?