How do commodities traders make money?

I have some friends in finacial planing and ehy have to chase people around for their money to invest with them. Do commodities traders do the same thing? do they chase people around to park their money with them and they trade on their behalf? How do they make money? I am quite new to this area but I have heard you can make a lot of money and also lose a lot of money. Do you have to study finance to go into that path or any degree will do as long as you know the right people? Can somebody alsogive me a webste where i can read some examples of how trading in comodities work? I am also looking for somebody to reccomend me a book on the subject.