Beauvoir, in Biloxi Mississippi, has long been a house museum run by the Sons of Confederate Veterans. Recently a library was opened in the house and is billed as the "Presidential Library" of Davis, the one and only president of the Confederacy. Definitely a unique spin on the idea of a presidential library, and illustrative of how these libraries serve multiple purposes. Here is a recent article from the LA Times on the library.
We have many books on the Civil War of course, including biographies of Davis, as well as much on the history of the "Lost Cause" and so forth. Databases like JSTOR and America: History & Life would be of interest too for journal articles.