How do you build a retaining wall for a garden?

Q: we just put up a new fence, but the thing is, my fiancé wanted it to look level instead of it sloping downwards with the hill that’s in our yard, so now at the far end, there is about 8 inches of a gap between the bottom of the fence and the ground. So we've decided that we're just going to build it up when we start planting there. i figured with the amount of dirt/mulch needed to reach that level we're going to have to put in some type of retaining wall or else we're just going to have to keep building it up after it rains, its windy, whatever.

so, if the yard was flat, I could figure this out because it would just be like 2-3 rows of whatever stone we're using, but the fact that its not flat, but we want it appear to be flat.... that’s where I’m lost. the stone we're looking at are 2"tall, so we figured for that part
That’s closest to the house it would be 2 stones
tall, and the farther part would be about 4 or 5 stones tall.

So, how do you make it build up and still look flat? i figured you start at the lower end, but how do you know where to stop with that row? Do you know any good websites that could explain it? The only ones I’ve found are for the same height all the way, which isn’t helpful. Thanks !

A: We live on the side of a hill and have many retaining walls of various heights and types.

We have a couple made from keystone concrete blocks. They run into the side of the hill. We began by starting at the low end and laid one row of level blocks until one of them was almost completely buried in the hill. We added a second row and it "died" in the hill about one block further. We continued this process until we got the height we wanted.

As a matter of interest, we some retaining wall made from concrete, some with brick and mortar, some with railroad ties and some with the concrete keystones. All of the walls are about 13 years old. The brick and mortar walls have held up pretty well but one section has had to be repaired due to a large crack. They railroad ties are all beginning to decay and some will need to be replaced soon. The concrete keystones are a solid as the day we put them in.

The bottom line, I would never use railroad ties again but only the heavy concrete keystone blocks or something similar. If you check around, there are some new designs similar to the keystone that is available at most home centers. These look more like field stones and are much more attractive than the ones we used.