Must read:
Master The Markets - Tom Williams
Trades About To Happen - David Weis
The Three Skills of Top Trading - Hank Pruden
The Trader's Book of Volume - Mark Leibovit
Investing With Volume Analysis - Buff Dormeier
Value in Time: Better Trading Through Effective Volume - Pascal Willaim
The Secret Science of Price and Volume - Tim Ord
Trading On Volume - Don Cassidy
Sentiment in the Forex Market: Indicators and Strategies To Profit from Crowd Behavior and Market Extremes - Jamie Saettele
Trade Stocks and Commodities with the Insiders: Secrets of the COT Report - Larry Williams
The Commitments of Traders Bible: How To Profit from Insider Market Intelligence - Stephen Briese
All Jim Kane Books (Fibonacci)
Superstructure Trading - Ken Chow
Fibonacci Trading: How to Master the Time and Price Advantage - Carolyn Boroden
High Probability Trading Strategies: Entry to Exit Tactics for the Forex, Futures, and Stock Markets - Robert Miner
If I remember of more books I will update this post, but in my opinion, the books listed are the ones you should be reading and reading and reading again.