Back to recommended books, I'm personally interested in the subject of the border conflicts - in my opinion, that was the 'real' Civil War (the larger conflict was closer to a clash of civilizations). An under-researched and over-romanticized topic. A couple of books worth reading:

O'Brien, Sean Michael / Mountain Partisans: Guerrilla Warfare in the Southern Appalachians, 1861-1865

Fellman, Michael / Inside War: The Guerrilla Conflict in Missouri During the American Civil War

I'm usually not a fan of historical fiction, but Woe to Live On by Daniel Woodrell is worth reading (NOT the same thing as the cheesy movie Ride With the Devil, based upon Woodrell's novel).