You have to develop your own trading system simply by practising every day and following markets.If you are a beginner, i suggest you to use Marketiva, which is a very good platform to start trading with and very easy to use.Marketiva gives you 5$ real For free! to start trading so you don't have to deposit and if you made profit from it you can cash out, this is why it's very good for beginners. Their platform is very easy to use and they have support during trading hours.To open your account please visit
http://www.marketiva.com/index.ncre?gid=3371