This is a good how to illustrate a children's book blog post,
http://muddycolors.blogspot.ca/2013/04/how-i-make-picture-book.html, and it even has a panda!
I have a couple of his books in my collection that I would recommend - Chloe and the Lion written by Mac Barnett and illustrated by Adam Rex, and Tree Ring Circus written and illustrated by Adam Rex.