The picture on the left is what your cube should look like at this point. Now we are going to do the center layer. The top or white part should end up exactly as it looks now, after every move from this point forward if it does not then you have done something wrong.
The first thing to do is find one of the edges that needs to be put in the center layer.
They will be in the bottom layer or in the center layer in the wrong spot. Try to find one on the bottom layer. Now hold the cube so the place that the edge peace needs to be is on the left hand side and in the front. Now turn the bottom layer until the edge peace you are trying to move is on the front.(the part facing you) Then do the following move.
Ok that is the only move you need to solve the center layer. There are some more moves that will make it faster in the extra algorithms page. But we are trying to use as few moves as possible, seven to be exact.
If you could not find an edge peace on the bottom layer then just do the move above and the cubelet that is in the center layer will the be on the bottom.
Now if the cubelet went to the correct place but is backwards then do the move again and then realign as was first stated and do it one more time. Your rubik's cube should now look like the picture below. So move on to the bottom layer section located in the links on the left hand side of this page.