Continuing on the Ender series by Orson Scott Card, he also has Home Bound, Heartfire, and the spin off from Ender, the Ender's Shadow Series.

Heartfire is sci-fi mixed with a little history, and the Shadow series begins with the same story line as Ender, from a different child's point of view. Home Bound is a little slower but still a great read.

I was first introduced to Orson Scott Card in college. He actually came to speak to our class on the Ender series (one of my most treasured items is my Ender book that he signed). He is a truly amazing man, who honestly feels that children are little people and should be treated as such. He came under severe criticism for the use of children in his books but has stood firm and continued to write on that vein.

Personally I agree with him, I never remember myself being a "child" with no stress, no worries, etc. (And I had a great childhood!) But I always saw myself as a person, who often got in trouble for daring to talk about "adult" subjects.

Orson Scott Card's books all give children a sense of pride and the feeling that they can do things that make a difference in the world no matter what their age is. While at the same time his books are strongly based on moral principles of right and wrong.

My husband and I still have all of the series and have read them multiple times so they are not just for children, but they are a strong basis for children to start with. It is amazing that the Ender series has been used from 8th grade to Master's programs. Each getting different aspects of the story, talk about a talented writer!