Sir or Ma'am,
Below is the link to a page on the Georgia State Library and Archives web site that may be of assistance to you and get you started.
You may want to also read the book, "Joe Brown's Pets: The Georgia Militia, 1862-1865" by William R. Scaife, William Harris Bragg.
Respectfully,
Gerald D. Hodge, Jr.
War Between the States Historian
Historian: 39th Georgia Volunteer Infantry Regiment
http://39thGAVOLINFRGT.homestead.com/39thHomepage.html