About the author
John Scalzi is an American science-fiction novelist and essayist known for fast dialogue, institutional satire, and ordinary people learning the rules of very large systems under pressure. His books include Redshirts, the Interdependency trilogy, and the Old Man's War series.
Old Man's War begins with elderly recruits receiving new bodies and entering an interstellar military they barely understand. Later books widen the frame to colonies, diplomacy, soldiers outside the first narrator's view, and the political cost of maintaining the Colonial Union.
Where to start
Begin with Old Man's War, then continue with The Last Colony, The Human Division, and The End of All Things; volumes two and four are not currently available here.