This summer will be the 150 year anniversary of the Battle of Gettysburg, one of the deadliest periods of the Civil War. The three days saw record causalities and is also considered one of the turning points of the war. Instead of breaking out a dusty nonfiction tome, consider The Killer Angels  by Michael Shaara. This fiction book does a good job at adequately describing the events that did occur, but shines at getting into the heads of the major players. We meet Lee, Longstreet and Chamberlain and start to understand their thoughts, positions, opinions and fears as they prepare and head into battle. This is well researched, and really readable. The maps give you a good visual perspective as well.
One of the things I love most about history is not only learning the outcomes and the details of the events that took place, but investigating the other possibilities, thinking about the what-ifs, and figuring out the decisions that went into what really happened.
If you are less interested in battle details, and lean more towards stories that show the impact of war on the general population there are some great Civil War options as well. Cold Mountain  by Charles Frazier is one of the most well-known. Critics call it slow moving, and I admit that there isn't a lot of action but the three stories of Inman, Ada and Ruby and their journeys -- both internal and physical are really moving. The storytelling is lyrical and the book has a really rich sense of place. Lesser well known is a great novel, The Widow of the South , based on a true story of the Battle of Franklin outside Nashville, Tennessee. Carrie McGavlock is already mourning three small children when the Confederate Army takes over her house and uses it as a hospital for one of the bloodiest battle of the whole war. Carrie's determination make up the most interesting aspect of this book, and this is done quite well. With multiple points of view, the reader becomes invested in several stories of pain and hardship, but also survival.