Another good book is
Empire of the Summer Moon: Quanah Parker and the Rise and Fall of the Comanches, the Most Powerful Indian Tribe in American History by S. C. Gwynne
It was a finalist for the 2011 Pulitzer Prize.
http://www.nytimes.com/2010/06/11/bo...anted=all&_r=0
Also there's the old stand-by:
Bury My Heart At Wounded Knee by Dee Brown
http://www.amazon.com/Bury-My-Heart-...t+Wounded+Knee