Fortune provides an interesting collection of "the best advice I ever got" from a diverse pool of achievers.
From Jim Rogers:
The best advice I ever got was on an airplane. It was in my early days on Wall Street. I was flying to Chicago, and I sat next to an older guy. Anyway, I remember him as being an old guy, which means he may have been 40. He told me to read everything. If you get interested in a company and you read the annual report, he said, you will have done more than 98% of the people on Wall Street. And if you read the footnotes in the annual report you will have done more than 100% of the people on Wall Street.