Whether you intend to invest in individual companies or in funds, do a buncha homework before placin' your bets. Compare the candidates across time and in relationship to both their immediate peers and their overall market performance. Go over the balance sheets and FEC filings, press releases, and news stories ... both mainstream and trade press. Read up on the segment or niche occupied by the entity whose instruments or securities attract your attention. What do they do, who do they do it for, who else does it, why would anyone want it done, what is the outlook for expansion or contraction ... that sorta stuff.
Yahoo Finance makes a lot of info available, and there are plenty of other free resources on the 'net. By and large, any fee-based subscription advice or tipsheet service is good for its operators ... I'd avoid 'em, mostly. Do your own homework, and do plenty of iy.
The Wall Street Journal, The Financial Times, Bloomberg, Investor's Business Daily, CNBC/MSN Money and CBS Marketwatch all have pretty decent websites, though to access some features on some of 'em, you do have to buy a subscription.
And don't play with money you'd be upset about losin'.