Of course you know who Warren Buffett is; he's the most successful investor in the world--maybe of all times. But what do you know about his approach to business and investing? It's an approach that, over the past four decades, has made him richest man in America and the third-richest man in the world, and that has earned vast fortunes for his business partners and investors. But as Buffett himself will tell you, at the heart of any...