We used Devil's Tower National Monument Climbing Handbook by Guilmette, Carrier and Gardiner and Devils Tower Wyoming and The
Black Hills, South Dakota (#7 in the Classic Rock Climbs Series)by John Harlin II (Chockstone Press)
Sign in at the ranger's station before climbing
Bring big pieces of protection
Bring more water than you think you will need
Recommend two ropes for rappel
Be careful to stay in the same line of rappel stations. A climb or rappel to the side can be confused with the rappel you want.
Allow time for the approach if it is unfamiliar
The Durrance route does not end at the top of the tower
The rappel from the summit brings you to a lower part of the tower than the Durrance route start, so if you leave stuff at the base of the climb
you will have to hike back.