Quote Originally Posted by bigred
FTR Forums and experience. Both of these will make you a better play than any book will.
I would say that one should use all the methods possible. Play poker, read the forums, discuss about the game, post hand histories for discussion, watch poker videos (like dmang vids) and read books.

In addition to harringtons book; Pot-limit & no-limit poker by ciaffone and reuben, this one is most likely the best book for NLHE ring game.