I have read HOH1 or rather am almost through with it. I also just bought Caros book of poker tells
which i hear is a must have for any serious poker player's collection. And I got Johnny Chans book on low limit holdem which i havent read yet. I can say HOH1 is a great read, and contains alot of information and that would be the number 1 book to get for learning the game according to me. I think even though it is focused on tournaments, it still teaches you alot about pot odds
, table position, and starting hands, as well as some strategies that work quite well when implemented properly.