"Read'em and Reap" by Joe Navarro and Phil Hellmuth
The Next Generation of Tell Analysis
While Caro's book is great for beginners to understand their own tells and the tells of others, the science of tells has advanced. There's more to know about reading your opponents than "strong usually means weak and weak usually means strong." Joe Navarro's Read'em and Reap, fills in the gaps.
Joe Navarro spent years as an FBI analyst. His job was to know when people were lying, and these skills transferred perfectly to poker. Navarro now gives seminars all over the country on how to pick up cues at the poker table, and has distilled a great deal of that knowledge in his book "Read'em and Reap."
Read'em and Reap
In the book, Navarro provides pages and pages of body language analysis that can give you an edge in your poker games. He tells you what it is likely to mean if an opponent leans forward (he's strong) or if he slides his chips into the pot (he's weak), among the cues he analyzes.
Navarro stresses that cues do not always mean the same thing for every player, and it's important to establish a baseline for behavior so you know when a person is reacting to his cards and when he's just being himself.
Read'em and Reap won't necessarily make you a better poker player, but it will teach you to be more observant, both of your own behavior and the behavior of others, at the poker table. This level of vigilance and the tools to use it can definitely increase your profits.