Shawna Tenney is a Children's book illustrator and she keeps a blog on her process, recently she posted about creating a Dummy Book.
http://shawnajctenney.blogspot.com/2014/01/dummy-books-part-1-making-dummy-book.html
http://shawnajctenney.blogspot.com/2014/05/dummy-books-part-2-preparing-dummy-book.html
http://shawnajctenney.blogspot.com/