For this latest project, the redesign of sunshineorganics.ca, I'm first redoing the Admin interface, as it used to be a combination of Microsoft Access and PHP.
For the new Admin interface, I can do it from scratch, so I'm trying out the Yahoo Web Framework, I'm working with grids.css, reset.css, and fonts.css. It's neat.
Here's a good reference for the sfont sizes in YUI fonts.css.