There is no real Star Wars reading material for young readers (4-7 years) However, this first book in a series for 9-12 year olds is just amazing. It's very readable to a younger child (4-8) at bedtime. As soon as I started reading the book to my son (6 years old) it was an instant hit...with both of us.
It starts BEFORE episode I, when Obi-Wan Kenobi is a boy of 12 years and in Jedi Training hoping to become the Padawan learner of the rebel & loner, Qui-Gon Jinn before he turns 13.
My son got so into the book he would force himself to stay up to listen to more of the story! Obviously, this is not what you want to happen when you want your little Jedi to go to sleep. (However, it does speak volumes about the writing, the story, etc...)
I have a sneaking suspicion that we'll be reading the entire series. This first book, was that good.