From MarketWatch.com: 4 investment tips that you should never use - MarketWatch
Some good warnings on investing; e.g.,
"Many of us know a fair amount about a single industry. But this doesn't tell us anything about where future profits will come from. If I invest only in the industry with which I happen to be familiar, I won't have adequate diversification. And I'll undoubtedly miss out on many great opportunities, just because I don't understand them."