The fastest and most risk free way to make money in the markets is to identify a change of trend in a market as early as possible, take your position (long or short), ride the trend, and close your position before or shortly after the trend reverses again. Any market professional will tell you that it is impossible to buy at the lows and sell at the highs (or sell at the highs and buy at the lows) consistently: but with practice, it is very possible to catch 60 to 80% of many intermediate -term and long-term market movements.
To be able to do this, you first have to know what the different markets are. What market instruments are available, where and how they are traded, what the margin requirements are, and so forth. Given this information, the next step is to identify a way to find specific markets that may be good investment opportunities.
To do this, you could go to the library and do three or four years of research on all the markets in the world, but by the time you finished your research, you would have forgotten half of what you learned and still have been broke. The other alterative is to learn to look at charts.