First, we got back a month ago flying Delta through ATL. We had a 65 minutes scheduled layover. Made it in LOTS of time (about 20 minutes) before boarding even started. If you figure boarding starts ~20 minutes before departure, it only took us ~20 minutes to get from gate to gate.
General Information (going off memory)... ATL has 5 concourses, A-E. I think Delta has all of A & B, and part of C. There are ~40 gates in each concourse. To get from concourse to concourse, you go underground (around gate 20), and either walk (with or without moving pedways) or take a shuttle tram. The tram will stop at each concourse. I BELIEVE the direction you go down to the lower level is determined by which way you want to go (ie: if you're at concourse C and want to go to A & B, you'll go left, and if you want to go to concourse D & E, you'd go right). That way you only get the tram you want to go.
BTW, Atlanta Airport Information:
Second, one thing I did within the week before travel was go to
http://www.flightstats.com. You can use information there to find out what gates your flights will be arriving/departing from (at least historically) along with on time/late percentages.
BTW, we were at the back of a 757 plane to make our above connection. We also had time for a bathroom stop. Make sure everyone knows what they are carrying/responsible for.