re: Poker & Harrington on Cash Games.. is this book the creme de la creme on cash games or what?
I think the books are fine, but are really focused on fighting against very good thinking opponents. So for low limit online play, it's not optimal because it relies too much on not being exploitable and too little on exploiting weak opponents.
Also he doesn't go into the distinct advantages that you can go by properly exploiting HUD stats, which is crucial to online play.
Frankly, it's a good buy if you play live. For someone like me who mostly plays online, then becoming a member of stoxpoker for instance will give you more bang for your buck (although it is somewhat more expensive than the books).