I agree with all of the previous posters, though I'd add that you have to be aware of
the agenda of the source, and they tend to be mainstream. Finance tends to be
less biased.

I'd add:
http://www.reuters.com/finance/markets
http://www.zerohedge.com/

And ths site sometimes has economics news, but its main purpose is to provide alternative reporting:
http://www.newsbud.com/
(look up the background for Sibel Edmonds on wikipedia)