So, I found the two docs I was referring to which will teach you everything you ever wanted to know about interfacing with an LCD. I would attach them to this message but the forum won't allow PDF uploads, apparently.
Also, when I was at the Fridley Ax-man today, I found some 2x20 LCDs with LED backlights. Don't bother going up there- I bought all five of the ones they had.
I don't recall seeing any of those at the other two Ax-man stores either, but who knows. They were only $1.95 each, which blew me out of the water. I'd expect to pay at least $5-$6 for those from anywhere else. I actually have quite the collection, now- three 2x24s with EL backlight, five 4x20s with (I think) EL backlight, and these 2x20s with LED backlight, plus one 2x24 that has no backlight and that I think I remember breaking but I don't know for sure.
Perhaps a future course covering these things might be in order. If anyone wants one to play around with, let me know- I'm certainly not using them at the moment.