Trading us quite simple: Find a place with a lot of a certain good, something like 10+. Then buy almost everything of that good. Then go and find a place with almost nothing or nothing of that good. Sell all your goods there, and buy new ones. Repeat. Repeat... Or you may check the local prices (takes 3-10 in-game hours) After a certain time, it will come a text, some thing like this: Buying (item) here and sell it at (city) will make a profit of (value) per unit. Buy the item sell it at the city, and make a profit. (the higher your trading skill is, the better deals you get)