This is the motherlode of animation information. The International Animated Film Society is building a webpage of information that is unparalleled. If all they had online were scans of Norman Rockwell's Famous Artists Course, well, it would still be the best web resource ever. But they have so much more. John Kricfalusi is joining up with this site to produce the $100,000 Animation Drawing Course, featuring scans of classic Preston Blair instruction books. The course is worth $100,000, but it is in fact free. And Kricfalusi will critique your work online. Jesus.
That's not all. The site also features art from classic Golden Books (I'm looking at you now, Jackson!), layouts and model sheets (some of my favourite things), classic newspaper cartoons and comics, interviews and biographies, downloadable classic cartoons (I'm getting Chiquita Banana right now), and tons more.
Run, don't walk.