I've read Intelligent Investor and Security Analysis (1934 ed.) and bios of both Munger and Buffett, and I found Alice Schroeder's Buffett biography to be pretty good. It is long, but it covers a lot of stuff that he might not tend to mention as a public figure ... and you can see how his investment style evolved from Benjamin Graham style value investing into his present strategy.
Also Buffett wrote letters to his partnership during the 60s that give a simple explanation of his investment style and explain some of his larger non-securities investments: http://www.ticonline.com/buffett.partner.letters.html ... this would be how he thought when he was merely a millionaire.
Also Buffett wrote letters to his partnership during the 60s that give a simple explanation of his investment style and explain some of his larger non-securities investments: http://www.ticonline.com/buffett.partner.letters.html ... this would be how he thought when he was merely a millionaire.