What is a good piano course book for kids?!

I'm looking for a good book to use to teach my five and seven year old children piano!. I am classically trained, but would rather have them learn by chord progression!. I want them to enjoy more creativity and get more enjoyment out of it than I did as a child!. I kind of like the Usborne Piano Course, but it's hard to find!. What else can you suggest!?Www@Enter-QA@Com

---

---