Ender's game & Ender's shadow, by Orson Scott Card

I read Ender's shadow several years ago when it was on the Abe list, and enjoyed it a lot. It's taken a while, but I finally got back to the series, and this time read Ender's game, which is the 1st book in the series. These books essentially tell the same story from the perspectives of two different characters, and both are excellent.

Earth has been under alien attack for almost a hundred years, and the next attack is imminent. On earth, humans have genetically engineered children with military genius, and these children are sent to a space station battle school, where they are taught military strategy. Ender Wiggins is the world's best hope to survive, but he is young (six, at the story's opening) and has a lot to learn in a short time. His teachers manipulate behind the scenes, and the older students resent Ender's advancement as Ender struggles to survive the war games that take up most of the battle school curriculum.

Ender's shadow concerns Ender's right hand child commander, Bean.

These are science fiction at it's best - but don't take my word for it. They are on every core collection list I've ever seen and have won numerous awards for Science fiction. Great stuff!