Well, you didnt specify what level, but if its higher limits, some of the cloutier/mcevoy books will help, so will reading either SS, (but only for the aggression and mind set required, Doyle used his psychic abilities for most of his plays, so its not blind bluffing, its buying pots when others are weak, and the NL game he speaks of is from the 60's and 70's, its a different beast now).

Getting started in Hold'em by Miller and the rest of the 2+2 gang is supposed to have a decent LL NLHE section, but I cant say, havent read it.

I think Ciaffone has some decent stuff too I've heard, but again, aimed at higher stakes (ML+).

Low limit NL, well play the goods, and listen to others here that know more about NL cash than I.

For NL:
The last two years have seen an explosion of the use of tools such as poker tracker.

Many poker room myths have been put to the test and many have failed.

In reality your best resource is prob here or 2+2 - and then play 100 of thousands of hands .

Some books are really good - I liked Harrington... others are probably misleading in the internet context.

The boundaries have been pushed in NL but there's yet to bea great book published on NL ring. In truth it wouldn't be a great seller - it's highly mathematical - pl looking for quick boosts to thier game don't take kindly to the implications of probability distribution functions .

Tournaments are different because they are a closed mathemtical system - there is an str8forward optimal way to play them...