The Psychology of Poker by Alan Schoonmaker

The book deals with sizing up your opponents, but more importantly sizing up yourself.

The book starts with you doing a self assessment of why you play poker--if you're fooling yourself, it's as good a time as any to get it straight.  There is a very interesting section about the characteristics of a winner--probably the best part of the book.

The author then has everything broken down into Loose-Aggressive, Loose-Passive, Tight-Passive and Tight-Aggressive and he goes into some detail on how each style should play the other styles.  There are rating charts for each style.

I think the book is worth a look from the self assessment point of view, his advice here seems better than the advice vs. other competition.

Characteristics of Winners

1. Winners always demand an edge
2. Winners are obsessed with Winning
3. Winners have extreme self-control
4. Winners are brutally realistic
5. Winners concentrate intently
6. Winners think visibly
7. Winners admit mistakes quickly
8. Winners learn from their mistakes
9. Winners accept responsibility
10. Winners depersonalize conflicts
11. Winners adjust to changes
12. Winners are selectively aggressive

This was one of the first poker books I read and I've recommended it to lots of players. I was leaning towards being a habitual loser until I read this book and changed my ways

Id recomend this as a must read

JBaker is loose-passive-aggressive