Day traders are attuned to events that cause short-term market moves. Trading the news is a popular technique. Scheduled announcements such as economic statistics, corporate earnings or interest rates are subject to market expectations and market psychology. Markets react when those expectations are not met or are exceeded, usually with sudden, significant moves, which can benefit day traders.
By aggressively trading on margin he can produce 5% daily profits on the 100k buying power he will grow their 25k cash at the rate of 20% per day. The risk of course is that he will make a mistake that will cost him everything. Unfortunately, this is the fate of 9 out of 10 traders. The cause of these career ending mistakes is a failure to manage risk.
The first type of scalping is referred to as "market making," whereby a scalper tries to capitalize on the spread by simultaneously posting a bid and an offer for a specific stock. Obviously, this strategy can succeed only on mostly immobile stocks that trade big volumes without any real price changes. This kind of scalping is immensely hard to do successfully, as a trader must compete with market makers for the shares on both bids and offers. Also, the profit is so small that any stock movement against the trader's position warrants a loss exceeding his or her original profit target.
Intraday Trading Strategies require intermediate to an advanced level understanding of how different aspects such as intraday charts, trading indicators, candlestick patterns, intraday trading tricks work together. If you are a beginner, it makes total sense to understand at least the basics of these concepts instead of directly employing these strategies in your trades.

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.