This is linked from our blog but I had forgotten —
http://multimedia.journalism.berkeley.edu/tutorials/
They have online tutorials on Final Cut Pro, audio editing including Garage Band and Audacity, Photoshop, Soundslides…and so forth.
There are also tutorials on making media, not just tools. I skimmed through the one on making video — started really obvious, but had some good advice, points I hadn’t thought about. I think it’s worth going through their tutorials (which it’s easy to to quickly) for various media, just to see what they may say that you don’t already know. Especially, tof course, for whatever media you plan to use, but others as well.