The first step in the CFOP Method is to solve the cross. This means to solve (orient and permute) the four edges on the first face. This step is unique in that the cross is solved almost entirely intuitively. For a standard speedsolve, you can use up to 15 seconds of inspection to plan this step. In some cases, such as in the Reduction Method of a big cube solve, you will have to think a bit quicker since you're already being timed. Even then, though, if you've mastered the cross, it will only take a few seconds.
Most beginner methods will advise you to solve the cross on top. This is because beginner methods are often not too concerned with speed. Instead, they are designed to make solving the cross easiest for beginners. However, in the CFOP Method, it is most common to place the cross on the bottom of the cube. This will save you the time it takes to rotate the cross from the top to the bottom. This also allows you to see the entire top layer, meaning you can see more pieces that need to be solved. With the cross on the bottom of the cube, you are instead looking at solved pieces. Intuitively, it makes a lot of sense that you should be looking at the pieces you need to solve instead of the pieces that are already solved. Another viable alternative is to solve with the cross on the left. However, I am not comfortable with that placement and so I will not go into any further detail about it.
You shouldn't worry too much about solving everything in the correct position right away. Instead, make sure that you solve the cross pieces correctly in relation to each other. That way, you can just do a D, D', or D2 to finish the cross.
This page is still under development. More to come later.