Click here for a fairly comprehensive bibliography on Smith County, Texas, during the Civil War. It includes citations to journal articles and books, and links to online resources. The first section deals with the Civil War in general, followed by sections on the secession crisis, Camp Ford POW camp, the ordnance works in Tyler, and units raised in Smith County, including letters from Smith County soldiers.
The National Archives has recently digitized two documents related to the Ordnance Works:
Letters Sent by Lt. Col. G. H. Hill, Tyler, Texas, 1864-1865
Miscellaneous Record Book, Little Rock Arsenal, Arkansas & Tyler Ordnance Works, Texas, 1862-1865
The surviving issues of the Tyler Reporter newspaper have been digitized at Portal to Texas History:
Tyler Reporter
So have the three surviving issues of one of the Camp Ford handwritten newspapers:
The Old Flag
Some books written by survivors of Camp Ford published before 1922 appear in Google Books in their entirety:
Camps and Prisons: Twenty Months in the Department of the Gulf, by Augustine Joseph Hickey Duganne
Sketches in Prison Camps, by Charles C. Nott
Heritage Quest database now has Free Population, Slave, Agricultural, and Industrial schedules for the 1860 census online.
Brokenburn by 
The Seventh Star of the Confederacy by 
Texas, the Dark Corner of the Confederacy by