Few designers actually get recognition in the world of book publishing, but thankfully Molly Leach seems to be getting at least a little of it.
Molly is the brilliant designing mind behind many children's books including The Stinky Cheese Man. We're used to books breaking the rules these days, but The Stinky Cheese Man expanded the boundaries of what was considered acceptable in children's book publishing at the time (1992). She rearranged where parts of the book were traditionally placed; she melted type (pre-computer enhanced); she ran text off the page; she used several different fonts on a single page; she used extreme type sizes. The list goes on and on.
Probably the most important thing to remember about her work is that everything happens for a reason. Yes, it looks really cool when it's finished, but it certainly isn't random. (Please see some specifics in the Horn Book link provided below.)
The interesting part of the story of The Stinky Cheese Man is the fact that she is the wife of Lane Smith, the illustrator, so they were able to work on the look of the book together. Until Jon Scieszka (the author) presented the text he had written to publishers accompanied by both Smith's illustrations and Leach's design, he was turned away. The March/April 1998 issue of The Horn Book contains an article written by Scieszka that illustrates this specific situation as well as how the design of a book helps relay its message.
Barnes and Noble sat both Leach and Smith down for a short video interview which they posted on their site. I've shown it to my typography classes, and I've embedded it here.