Even good sites may have certain tools that aren't so hot. Some sites may make you poorer. And sometimes the problem is you.
Don't: Take investing advice from Yahoo Finance message boards.
Using a stock tip from "MSFTMan47" may cost you dearly. The discussion is usually more hype than substance.
Instead: Check out the forum Bogleheads.org. Many participants are investing pros who dish out sensible, low-cost buy-and-hold advice.
NEXT: Buying a car