Since I usually deal in the investment area of finance, the most beneficial advice I've ever heard comes from Warren Buffet. I can't really pick out one particular statement, but here are just a few that I like:
"Risk comes from not knowing what you're doing."
"Chains of habit are too light to be felt until they are too heavy to be broken."
"It takes 20 years to build a reputation and five minutes to ruin it. If you think about that, you'll do things differently."
"Rule No.1: Never lose money. Rule No.2: Never forget rule No.1."