There are a couple of other tools that I find usefull, one is a bucher's steel. What it does is to straighten the edge. Often, when a knife isn't cutting well the edge has gotten wavy, but does not need to be sharpened yet. A few swipes on a steel (with the edge laying along the steel) will true the edge up again. You can only use a steel so many times between sharpenings though, and with a steel less is usually more. Use one too much and you will end up dulling your blade. I also like to keep a block of wood handy whenever I'm sharpening. If you slice along a corner of wood it can help strip off grains of steel that are mostly loose, but still stuck to the edge of the blade.
Besides angle you need to think about pressure. People have a tendency to press their blades too hard into a stone. What can happen when you do this is forming a burr, a very thin strip of steel right on the edge that has no integrity and will fold over the first time you use your knife. This is the frustrating thing about learning how to sharpen because people say things like use "just enough" pressure for your stones to work. Well, how much pressure is that, well... you can feel the stones working, but you only know what that feels like if you use the right pressure... This is what experience is for. As a rought example, (that I just thought of sitting here, maybe someone else can do better!) Imagine trapping a mosquito under your finger. The force required to crush it is more than the pressure required to get a coarse stone to work. Fine stones require even less pressure.
Good luck, and keep asking questions! Also, have some other guys tell you what they do. They'll probably say that I'm nuts, but thats ok. I get my blades sharp and they do to!
