At the risk of disagreeing with Sheldon, I think a heavily dished rear wheel, like an 8 or 9 speed, is pretty hard to tension correctly, especially for an inexperienced builder. Straight guage spokes on the drive side make tensioning a little easier, and double butted spokes on the left side make the wheel almost as strong as a well built wheel with all double butted. After you've built a few (or many) wheels, you get a feel for it, and then an 8 speed is as easy as any other wheel.
EM