John Scalzi's "Old Man's War"

I'm presently reading John Scalzi's book Old Man's War. I became interested in John Scalzi (http://en.wikipedia.org/wiki/John_Scalzi) when I learned that he was hired as a consultant for "Stargate: Universe." When I was able to pick up Old Man War's at Books-A-Million for $2.97 plus tax, I decide to read it.