The book follows a child, named Ender Wiggin, through his training at battle school. He is recognized as a tactile genius and quickly progresses through school at a very young age. All his training is focused on destroying an evil alien race known as the "buggers". As would be expected, there are sweet battle scenes and plenty of childhood bantering.
One interesting point is that at the end of the book Card gives a quick interview. He talks about the book and how it came about - kind of like a special feature on a DVD. He also says that he was originally a Broadway play writer and that when he writes, it's meant to be spoken out loud. Therefore, he concludes, listening to the audiobook is the best way to enjoy his story.
Being that this is an award winning best seller, I'm sure many people have already read it. However, if you have not, I highly recommend it. It's an easy listen and really entertaining.