psychprof, as a 20D newbie too, here are my simple suggestions. (BTW, aside from a P&S Nikon digital, this is also my first DSLR after years of shooting with a Nikon F2).
To get used to my camera this past week, I shot in L/H JPG setting, but within two day's I started shooting RAW. I found shooting RAW, then converting to either .TIF or .JPG provided for better overall image quality as I did all my processing of the parameter's with the RAW file prior to conversion. Although I do have the camera set in Canon's 'parameter 1' mode, it really does not mean allot in RAW, as you have so much latitude to change these settings 'post processing'. You can change the white balance, sharpness, saturation, etc. all within Photoshop, EOS Viewer Utility, or Digital Photo Professional, without changing the RAW file (because it cannot be changed). Making these changes within a 'camera .jpg' would be very dificult, but is quite easy and forgiving in the RAW format.
So although I keep the camera in 'parameter 1', I only 'gain' from that because I have been shooting RAW+JPG mode, and those gains in contrast/shapness/saturation seem to provide the JPG files with more 'punch'. Other than that I shoot manual and bracket as necessary given the subject. Great thing this digital...you can see the results of bracketing immediatly following each shot Obviously I also change ISO as required, metering mode, and White Balance, but those can change for each condition. Within RAW, I simply keep my white balance on auto...if I'm shooting JPG's in addition, I change that setting depending on the situation. And again, you can change white balance while post processing the RAW file.
I do still shoot in sRGB color mode as I am still learning about this mode, and the differences which can be gained. But again, you can change this setting while post processing in RAW. In addition, you can go back and forth between B&W/color within the RAW file...even adding the B&W filters 'after the fact'.
Bottom line, I would not get too fancy with these camera settings, as everything is availiable to you in RAW processing. Everything else is simply having a good understanding of how to set-up a shot given the conditions you are dealing with.
Hope that helps a little....enjoy the 20D....what a great camera! I thought I would miss the Nikon, but I doubt it....although I will keep my Rollei 35, and a couple other rangefinder camera's for film work.