Some books that I've found to be particularly helpful are...
The Intelligent Investor (Benjamin Graham)
Common Stocks and Uncommon Profits (Phillip Fisher)
One Up On Wall Street (Peter Lynch)
Beating The Street (Peter Lynch)
Security Analysis (Benjamin Graham & David Dodd)
Berkshire Hathaway Letters To Shareholders (Berkshire Hathaway)
Modern Security Analysis (Martin Whitman & Fernando Diz)
The Alchemy Of Finance (George Soros)
You Can Be A Stock Market Genius (Joel Greenblatt)
The Little Book That Beats The Market (Joel Greenblatt)
The Dhando Investor (Mohnish Pabrai)
The Outsiders (William Thorndike)
The Wall Street Journal Guide To Understanding Money And Investing (Kenneth Morris & Alan Siegel)
The Psychology Of Money (Morgan Housel)
The Most Important Thing (Howard Marks)
Good To Great (Jim Collins)
Distress Investing (Martin Whitman)
Value Investing (A Balanced Approach) (Martin Whitman)
The Little Book of Common Sense Investing (John Bogle)
The Snowball (Alice Schroeder)
100 to 1 in the Stock Market (Thomas Phelps)
Mastering the Market Cycle (Howard Marks)
Expectations Investing (Michael Mauboussin and Alfred Rappaport)
The Essays of Warren Buffett (Lawrence Cunningham)
Creating Shareholder Value (Alfred Rappaport)
Poor Charlie's Almanac (Peter Kaufman)
Thinking in Bets (Annie Duke)
How to Decide (Annie Duke)
The Wall Street Journal Complete Real-Estate Investing Guidebook (David Crook)
The Vulture Investors (Hilary Rosenberg)
The Profit Zone (Slywotzky, Andelman, and Morrison)