I have grown weary of solving style sheet problems (it doesn’t seem fun, especially when you forget what style applies to what–something that the latest Dreamweaver has solved handsomely). I’ve found some good links and demos, but now I’m speechless.
Positionize Everything is the best site on style sheets out there now, including some great articles about debugging stylesheets and this amazing demo.
On another note, morphon has an excellent free CSS style editor. Highly recommended.