Hold 'Em Poker by David Sklanky
"THE FIRST DEFINITIVE BOOK EVER WRITTEN ON THE TEXAS-DERIVED WORLD CHAMPIONSHIP poker game...by a Pro Player"
Funny title. Obviously written at a time before holdem was a houshold phenomenon. Don't let that bother you. A great book that's been updated since its original publication in 1976.
I'll third that recommendation or Low Limit Holdem. And add Super System in there as well. It has a good section on limit holdem as well as NL and other games as well.
Do you guys know of any great books on NL Holdem' that concentrates on cash games rather than tourney? Super System 1 and 2 look good but seem to be a bit too broad instead of specialising on any one type of poker.