The basic strategy of news playing is to buy a stock which has just announced good news, or short sell on bad news. Such events provide enormous volatility in a stock and therefore the greatest chance for quick profits (or losses). Determining whether news is "good" or "bad" must be determined by the price action of the stock, because the market reaction may not match the tone of the news itself. This is because rumors or estimates of the event (like those issued by market and industry analysts) will already have been circulated before the official release, causing prices to move in anticipation. The price movement caused by the official news will therefore be determined by how good the news is relative to the market's expectations, not how good it is in absolute terms.
Finally, keep in mind that if trading on margin—which means you're borrowing your investment funds from a brokerage firm (and bear in mind that margin requirements for day trading are high)—you're far more vulnerable to sharp price movements. Margin helps to amplify the trading results not just of profits, but of losses as well if a trade goes against you. Therefore, using stop losses is crucial when day trading on margin.
You're probably looking for deals and low prices, but stay away from penny stocks. These stocks are often illiquid, and chances of hitting a jackpot are often bleak. Many stocks trading under $5 a share become de-listed from major stock exchanges and are only tradable over-the-counter (OTC). Unless you see a real opportunity and have done your research, stay clear of these.