Almost over, but we've got one very important topic to cover—clean-up and commenting. You may be able to read your material just fine now, but when you come back in a week, or a month, an organized material with some useful comments will be a lot easier to understand.
The first step is good organization. As we've seen, data in the Material Editor flows right to left (the inputs of our nodes are on the right, and the spit out data to the left). Take some time now and organize your nodes so that there's no backtracking (the Texture and Constant nodes should be on the right, and the Multiply nodes should be to their left). Also organize things to minimize crisscrossing lines—the nodes controlling Diffuse should go on top, with the ones controlling Specular below. Try to get a network that looks like the following screenshot:
The next thing we can do to organize our network is label the nodes. For instance, what if you decided at some point that...