You will also want to get registered on the official Rock N Roll Marathon website. Register for the race at RunRockNRoll.com.
Locals may be interested in signing up to train with Fleet Feet. You can find more info on their website here FleetFeetNashville.com.
Please feel free to visit the Run 4 Others website Run4Others.com to register with them as well. You will have access to their training routes and weekly newsletters.