I do - both options and stocks.
I wish there was a way to tell that a company is gonna be a good one; it's more about percentages between winners and losers, and having a strict discipline in terms of what you will buy and when you'll take winnings or cut losses. Emotions typically get in the way. It's a lot of work.
If you want to read about different approaches to trading, check out the "Market Wizards" books, which are interviews with currency, option, stock, commodity etc. traders (all tops in their field) and looking at their approach. They're all very different (some do a ton of research, some go by "gut") but all have a LOT of discipline. Most of them have been wiped out at least once. (!)
A good understanding of economics goes a long way - understanding the correlations between the job market, home building, the gold market, etc. etc. etc. can help show general trends - what will be bullish or bearish for banks, or metals, or tech and so on...
The one guarantee I can give you: you WILL lose money. You'll also make it - again, it's the percentage of winners to losers that matters in the end. Anyone who tells you otherwise (there are a LOT of "trading systems" and self-promoting gurus that promise outrageous returns) is selling you snake oil. Think of it this way - there are far more guaranteed returns in selling a "system" to the masses than actually trading that system.
