quote:The Mental Game of Baseball: A Guide To Peak Performance- H.A. Dorfman KArl Kuehl
The Mental ABC's of Pitching: A Handbook for Performance Enhancement- H.A. Dorfman
Heads-Up Baseball: Playing the Game One Pitch at a Time- Tom Hanson, Ken Ravizza
These will help you Mentally get a hold on the inner half of the plate.
Along with Coaching Pitchers by Joe "Spanky" McFarlane will help you with some drills, same with The Lousiville Sluggers All You Need To Know About Pitching.