The effects and animations we have seen time and again all rely on the power of Cascading Stylesheets. To incorporate the visual flourishes we desire in our sites, we may need to turn to these CSS resources for guidance.
The W3C's CSS home page provides links to tutorials, specifications, test suites, and other resources: http://www.w3.org/Style/CSS/.
Dave Shea provides this helpful CSS Crib Sheet in an attempt to make the design process easier, and provides a quick reference to check when you run into trouble: http://mezzoblue.com/css/cribsheet/.
This site includes a catalog of CSS browser bugs along with explanations of how to overcome them: http://www.positioniseverything.net/.