This is a great book that my grandmother bought for me when I was a child, and again for my children, many years later.
The Jolly Postman, in this book, must deliever letters to various storybook characters (baby bear of the three little bears, puss in boots, the witch who lives in the gingerbread house, just to name a few). "Real" letters are included in little envelopes, as you go through the story, allowing the child to read the mail of these favorite fairy tale characters.
The story line is a lot of fun, the letters are very entertaining (when I was a kid, all my 'letters' looked terribly torn up from how often they were read), and it encourages children to read, just because of how fun it is!
This is a great book for any child (or even adult, I think I read the one I have for the kids more often than they do).