Jean Edna Karl was an American book editor and writer who specialized in children's and science fiction titles. She founded and led the children's division and young adult and science fiction imprints at Atheneum Books.
Good book, with helpful and practical advice for those who want to write (and not illustrate) picture books. Some of the tips would, I imagine, also be useful for other kinds of writing.
The truth is that I skimmed this book; it's organized like a true outline, so it was easy to do. Unfortunately, the vast majority of information in this book isn't necessarily useful for someone who's already been writing, and much of it is repetitive. It is, however, a good resource for a complete novice.
This textbook is okay, and presents all of the main principles and concepts of how to write picture books, as well as some fairly useful insights into selling them too.