My friend has come out with a new book on the Battle of Chickamauga. I have not read it yet, but having worked alongside Lee for nearly 5 years I can predict an informative and enjoyable read.
In addition, today also marks the beginning of ranger guided tours in honor of the 150th anniversary of the Battle of Chickamauga. More information can be found here. If you are in or near the area you might want to check them out.