In my view, there are two general components to the mental part of tennis. There is the internal aspect. That is what happens within your mind during the game: How you feel. What you think and what you say to yourself before the match and in between points.
Then there is the strategic part of the game. This inculdes your strategy and your battle plan.
Both of these are addressed in detail in the new book Zone Tennis.
http://worldaudience.powweb.com//pubs_bks/ZoneTennis.html
For more tennis tips, visit www.stayinthezone.com