Some readers asked where to start in order to understand RU. Craig Burton has good animated walk-throughs. I read most news sites and blogs (you guessed, that’s a lot of sources) through MUOTD, and you should at least look at the demo.
07/15/01 update: they’re not on the home page anymore, find them here.
07/23/01 update: a mention of Craig Burton I hadn’t seen.