The basics of mining are really simple. In most systems there are asteroid belts or belts, denoted by the upside down triangle icon, as shown in the following image:
In these belts are asteroids or roids of various types of ore. Fly to these belts in a ship with mining lasers equipped, and start mining a roid until your cargo hold is full. You will make ISK when you sell the ore you have mined. Of course, nothing in EVE is ever that simple, so we will look at everything in much more detail.
As I mentioned before, in most systems there are belts with roids of various types of ore, but what should you be mining? The general rule is to mine the highest grade ore you can find first, and then move on to the next highest grade ore, and so on. But there are so many different choices. So which is the highest grade ore? Well, that depends on several factors. Let's take a closer look.