Many traders use many different scanning techniques/paramaters/criteria
e.g. scan for stocks with price above 13ema scan for stocks that have a volume and price increase from the previous day scan for stocks with a positive MACD scan for stocks with %K above %D
Some other traders look at the most discussed stocks on HotCopper...follow the crowd...follow the volume
Good Luck...keep reading, make a trading plan suitable to you, follow that plan, paper trade, start trading with a small outlay, use stop losses, take profits