This book is not a stand-alone book, it is a sequal to Ender's Game. I read this book around 1996. I heard about Ender's Shadow a month or two ago and have recently finished the series. I have read all of the Ender and Shadow series and will continue to do so as long as they keep being written.
If you are not familiar with OSC, he is also the author/playright of the Abyss! Ender's Game is planned to be made into a movie by WB and the producer of a Perfect Storm.
This book is about Ender's life off-planet after having saved the world. This book is very philosophical and has less action. It is a not as fast paced as Ender's Game. I would say more about the book, but I hate people giving away any information about books and movies so I won't.