By now you should be able to solve the first two layers of the cube on your own and orient the last layer (make the top face yellow). We will permute the pieces of the last layer in two steps just like we did for orientation. We will permute the edges first and then finish the cube with the corners.
I am Bob Burton, Rubik's Cube Expert, and I am teaching you how to solve a Rubik's Cube. Now that we have the first two layers completely solved and we have the last layer oriented, we need to permute the edges of the Rubik's cube. To solve this we need to first put the edges in such a way that one of them is correctly permuted. That means that one of them will line up with the correct center. If we rotate the Rubik's cube so that we have that, notice that the other three are wrong. If we have two edges that are correct, and that's the only way that we can have the correct edges, then we have more to do. First I will show you the easy case. If one of them is correct, we're going to move to right side down twice, the top side to the left. We then go right side up, top side left, right side down, top side right. You have seen that part before in a different algorithm. We then go right side down, top to the right, right side down, top to the left, right side down. That completely solves the last layer edges of the Rubik's cube.
Sometimes it's possible that no matter what we do we have either zero or two edges correct. That happens when the Rubik's cube edges are correct across from each other. If that's the case, we first do the algorithm pretending that only one of them is correct. Right side down twice, top to the left, up, left, down, right, down, right, down, left, down. Now, we can arrange the Rubik's cube so that we have, again, only one correct. We put the correct piece in the back always. We then do the algorithm that we already know; down twice, left, up, left, down, right, down, right, down, left, down. Notice that we still have one correct. What it does is it cycles three corners, three edges clockwise. Sometimes since we're rotating three edges, we need to do it twice. This is one of those cases. Down twice, left, up, left, down, right, down, right, down, left, down. We're now ready to move on to the last step, permuting the last layer corners of the Rubik's cube.
This is the goal of this step. If you can rotate the top layer to line up all four edges, you can move on to the next step. This will happen 1 out of every 6 solves.
This is the algorithm you need for this step. With exactly one edge lined up with its center, put it in the back. Then do right side twice, top side clockwise right side up, top side clockwise, right side down, top side counterclockwise, right side down, top side counter clockwise, right side down, top side clockwise, right side down.
Because the edges might need to be permuted in one of two possible directions, you may need to do the algorithm more than once. Note that it is possible to rotate the edges so that a different edge lines up with its center and perform the algorithm only once, but let's worry about that later.
Occasionally, you will not be able to have only one edge solved no matter how you rotate the top layer. If you can only have exactly two opposite edges solved, you can put them in the front and back and perform the algorithm above so that you only have exactly one edge solved when you've executed the alg. Then just rotate so the solved edge is in the back and perform the algorithm again.