Lynda.com is essentially a site of video tutorials. It's a paid site and members have access to all the videos. However, they also have a good selection of free videos that will at least get you started. I would recommend looking at editing in Final Cut Pro and in iMovie.
Another great site filled with video tutorials is Adobe TV. You can learn Premiere Pro or you could also give After Effects a go (the software I used to create the community board video). I've linked the tutorials for the latest versions (since school has the latest versions), but you can also find tutorials for older versions of the software on Adobe TV too.
Final Cut Pro X is Apple's latest version of Final Cut. You can get a free trial of this and the Adobe software for a month if you're interested in working at home.
Turns out that Mac Pro Video and Ripple Training both allow limited previews but cost money to view the whole tutorials so I did some more hunting for free introductory videos: see below.
Apple actually has an entire host of iMovie tutorials and lessons online that are easy to understand and follow. Just click a lesson and there are video tutorials as well as written instructions.
This site (Izzy Video) has a good list of videos.
And here's one of a list of videos from Lynda.com teaching Final Cut. (Click link below to go through.)
Final Cut Studio Overview | by Damian Allen