I am having the hardest time understanding how to keys and alpha channels work, much less how to incorporate them into graphics on my video.
Can someone recommend a book, tutorial, or webpage that explains
the concept and technique of working with keys and alpha channels?
Basically, keying is separating an element out of a picture or scene. If you make a selection, you can save that selection as a "mask". The pixel information of this "key" or "mask" is stored in an Alpha channel, so you can reselect and make changes to it it at any time.
You can either manually build your mask ( key), or use "plug-ins" to make the process of selecting easier.
If you save a picture or video with alpha channels ( choose a format that supports Alpha channels like Photoshop "psd' or AE "Quicktimes Millions colors +" format ) you can import the files into other applications and do whatever you need to, to either to the Alpha and/or the "masked out' elements.