be nice to have a link that just talks about audio/video principles and concepts, etc.

This is a pretty good one:

http://www.hometheaterhifi.com/volume_1_1/

yeah hometheaterhifi is a good resource. i like them a lot, but wish they did more. that article(s) is a smidge dated, but still good. they are doing a ssp shootout that should be interesting, much like what they did for dvd players and something else i think.