The way to solve the first seven edges in the beginners' method of rubikscube.info is actually poorly explained; this step is very intuitive and should not be viewed as a set of algs to learn. The basic ideas are:
- If the edge you're trying to solve is located on the middle layer, assuming its slot is on the top (if not, do the appropriate L or R move), do U or U' (depending on the orientation of the edge) to put the slot on the middle layer, then the appropriate M move to put the edge in the slot and U' or U back.
- If the edge is in a wrong slot, or in its slot but flipped, first put it on the middle layer by proceeding as above and then solve it.
- In borh cases, you must have a still unsolved slot facing the slot you're trying to solve. That's why you solve only three L edges in step 4: to keep an unsolved slot on the L layer and keep it in LU position while solving the R edges.