It’s worth taking your time to read Karen J Lloyd‘s Storyboard blog
She writes with such honesty about a part of the animation business that isn’t often discussed on the web. She includes comprehensive tutorials and some very useful downloads.
I’d advise starting with her series of posts that dissects Wall-E, and see her demonstration of what is being conveyed to the audience, shot by shot.
An excellent resource, that is now featured in the links page.