Cool. Those types of stories are good for the kid and parent. Keeps both entertained and gets through a common problem between both.
Buy the Sunday New York Times, and get hold of their Book Review section; there's usually a kids section with the new books coming out. Note down the publishers and start sending out queries just like what you wrote in this thread.
Get this book and read through it:
http://www.amazon.com/exec/obidos/tg/detail/-/0761525157/103-4209004-4604620?v=glance