Jack Koehler's "Upscale One Pocket" is good for starters. "Winning One Pocket" and "Shots, Moves, and Strategies" edited by Eddie Robin are both good but pricey. Tom Wirth's book "One Pocket: A Game of Controlled Aggression" is, in my opinion, the best thing in print on One Pocket today, worth every penny.
There are some good DVDs available, both how-tos and tournament matches. Billy Incardona's is good, also Scott Frost. If you want to work on your banking, "Bank Pool: Secrets of a World Champion" by John Brumback is a must-have. If you have access to anyone who has a good run of Billiards Digest Grady Mathews' monthly column is great. I have them all:grin: Lots of stuff on youtube.