Consider other works of classic science fiction, such as Phillip K. Dick's Do Android's Dream of Electric Sheep? or The Year of the Flood by Margaret Atwood.
Consider other science fiction novels about children, such as A Wrinkle in Time, by Madeleine L'Engle or The Ear, the Eye and the Arm, by Nancy Farmer.
Other works in the Ender series provide additional perspective on the original novel, especially Speaker for the Dead, Xenocide, and Ender's Shadow.