Al Brooks "Reading Price Charts Bar by Bar". Just a 5 min chart, 1 lonely 20 EMA, and retracement entries. Start on page 118, and read it till you breathe it.
Look, I mean there's no such thing as a "must read" in trading .. . You really have to find your own path, your own edge. I've found Schwager's Market Wizards to be a great source of information on different trading styles. I know a lot of people respect Michael Covel's work on the turtle trading system and trend-following, although I haven't read his books yet. You might want to check them out. It's the story of a system which has become quite popular. In any event, keep learning, keep searching . . . I've found my edge, and I'm sure you'll find yours one day.