[KenProspero]

If I were to rank all he poker books as far as usefulness to a new-intermediate player, Theory of Poker would be first, and Psychology of Poker would be second.

First of all, it gives you the tools to analyze your 'natural playing style'. In all liklihood, you will see yourself in the descriptions Dr. Al gives, and you will recognize your natural style of play (even if you thought your were TAG). After this analysis, you can begin to make the decision of whether you want to play poker to satisfy your emotional needs, or whether you want to play poker to win money. If you understand your own playing style, through conscious effort, you can mold yourself to the player you want to be.

Further, if you can identify personality traits in your opponents, you can make tremendous gains in reading them and determining how they play.

From these two areas alone, your long-term profits will increase tremendously if you understand what Dr. Al is saying.