I read this article many years ago, and it is still relevant. Here are a few snippets from the piece. Check out Aaron Shepard’s article for 10 more myths and truths about picture book writing.
http://www.aaronshep.com/kidwriter/Truths.html Aaron Shepard
MYTH: Children’s books are easier to write than adult books.
TRUTH: Good writing is difficult no matter what the reader’s age—and children deserve the best.
MYTH: Since my kids/neighbors/students like my story, it will make a great book.
TRUTH: Your kids/neighbors/students may like it only because it’s yours, or because they enjoy your reading.
This does not impress editors.
MYTH: To sell my work, I must get an agent.
TRUTH: Though it has become harder to sell children’s books without an agent, you can still do it—and getting an agent may be as hard as getting a publisher. Agents are more useful and available once you’ve sold on your own.
MYTH: My chances are better if I submit to small publishers.
TRUTH: Not unless your book is specialized. Small publishers issue fewer books and must often be cautious in their selections. Large publishers can afford to take an occasional chance.
MYTH: When submitting, I must protect my ideas from theft.
TRUTH: Theft by children’s publishers is rare. Ideas are plentiful, so editors are more interested in finding writers who can handle ideas. In any case, copyright law protects your work—without any official registration or notice.