Just finished watching this documentary about Georgia's involvement in the Civil War. It's basically an overview of all the battles in North Georgia leading up to Atlanta, and then it ventures into Sherman's march. As it covers a lot of ground, it doesn't really get into deep details about any of the events, especially the march itself.
It was produced by GPTV about 5 years ago, and it is very well done. Like I said, it doesn't go into any great detail, but it does serve as a good primer for people interested in Georgia's role. Definitely worth tracking down. It also features Dr. Gordon Jones of the Atlanta History Center, who has been kind enough to talk to me about my project. Here's a great piece he did on Atlanta and it's Civil War Resources.