Here are some resources I've found helpful and that I hope you will find helpful, too.
Writing and Illustrating
• Writing With Pictures, by Uri Shulevitz. Start here. (Out of print but that's why we have eBay.) The best book out there on writing and illustrating picture books. The chapters on the printing process may be outdated, but never the chapters on storytelling. See also Picture This: How Pictures Work, by Molly Bang.
• How to Write a Picture Book, from author Mac Barnett and editor Taylor Norman.
• Tips and techniques from Marla Frazee are here.
• An example of a book dummy — an early dummy for my book The Racecar Alphabet — is here.
• Visit the children's collection at your local library for a sense of what's out there, the old and the new. Leave sentimental memories and associations at the door! Read actively, with a fresh and critical eye. Consider the books from the perspective of an adult and a young person. Which books do you find engaging, moving, interesting, funny, beautiful, true, convincing, and why?
Publishing
From the outside, the publishing world may appear mysterious, bordering on inscrutable. (Sometimes it appears so from the inside, too, assuming I have actually seen the inside, but who knows?) These resources will cast a little light into the dark corners:
• The Purple Crayon. A good introduction to children's book publishing is here. Answers to questions about agents — do you want one, and how do you find one? — are here. From Harold Underdown, author of The Complete Idiot's Guide to Publishing Children’s Books.
• Society of Children’s Book Writers & Illustrators. SCBWI runs a web site, publishes newsletters, holds conferences, and conducts guest speaker/panel discussion series. SCBWI events offer the chance to meet other people active or interested in the field and to put yourself in contact with editors, art directors, and other publishing professionals.
• How to choose a publisher, in five easy (?) steps, from First Second Books, here.
• So, You’ve Written a Children’s Book…Now What? How to submit a manuscript for publication (and how not to), from Ariel Richardson at Chronicle Books.
• Children’s Writer’s and Illustrator’s Market. A guide to how and where to submit work, with interviews with people in the field. (Published annually. If I've failed to update this link recently, look for this year's edition.)
• Finally, a note to authors about illustrators: Do not worry about finding an illustrator for your manuscript. Editors and art directors know more illustrators than you (or me), and they are professionals at making happy matches between stories and artists. Therefore unless you are hoping to work as both author and illustrator yourself, manuscripts should be submitted to publishers without art or artist attached. There are exceptions to this rule but they are, truly, exceptions.
• And really finally: The Life Cycle of a Book, by Elisha Cooper.
Happy writing, happy drawing, and good luck!