As with bullish swing trades, if the reward-to-risk ratio is acceptable, you could enter your trade using a sell-stop limit order. This would result in selling the stock short once it hits your entry point. Selling short is the process of borrowing shares from your online broker and selling them in the open market, with the intention of purchasing the shares back for less cost in the future. An alternative to short selling would be to buy an in-the-money put option. If you choose to use options, you would use a contingent order to buy the put after the stock hit the entry price.
Market data is necessary for day traders to be competitive. A real-time data feed requires paying fees to the respective stock exchanges, usually combined with the broker's charges; these fees are usually very low compared to the other costs of trading. The fees may be waived for promotional purposes or for customers meeting a minimum monthly volume of trades. Even a moderately active day trader can expect to meet these requirements, making the basic data feed essentially "free". In addition to the raw market data, some traders purchase more advanced data feeds that include historical data and features such as scanning large numbers of stocks in the live market for unusual activity. Complicated analysis and charting software are other popular additions. These types of systems can cost from tens to hundreds of dollars per month to access.
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.