There are a few threads around that touch on this, but I will get you started in the reading at least. Do yourself a favour; if you're going to get into stocks, read Benjamin Graham's
Intelligent Investor first. One of the most important things you need to do early on is determine whether you're an investor or a speculator. Don't be a speculator. (Hint: There are many who think they're investors when they're really speculators.)
Other than that, clear your bad debts before even thinking about investing, or you're likely just wasting your time and money.
Also realize we're in a cyclical bear. It's a bad time to be in the markets unless you understand value investing and contrarian strategies, in which case you'll have much to do right about now...buying up all of those undervalued stocks.