Three Cups, by Tony Townsley, Mark St. Germain, and April Willy. Three Cups tells a story of a child who is given a way to place money that is given to him: one cup each for giving, saving, and spending.
I got the book for my own kids, and sadly, it was a couple of years too late. The book is written at a level of a boy or girl who's around age 4 or 5. It's probably the type of book which is best read to a kid.
That said, it's a great little book, and the story is interesting enough that the kid who hears or reads it doesn't realize he's being preached to or being taught.
Yet, they are being taught an important lesson: it's good to know how to manage your money, and it's good to spend some, to save some, and of course, to give some.
I like this book a lot. Just wish I would have gotten it a few years ago.