Warren Buffett writes a letter every year to his shareholders. You can find them at
http://www.berkshirehathaway.com/letters/letters.html. They are gems of straight forward writing and advice. He looks at himself as a teacher and partner to his fellow investors. These letters are probably as valuable as an M.B.A. Also, his speaking on YouTube is worth a watch. Here is the first part:
http://www.youtube.com/watch?v=DfuXKpMFUjc. "
The Snowball" written by Alice Schroeder is also highly recommended for background on this legendary investor.
