» The latest CSS tools

Check this out: the latest in CSS templating.  It is a listing of common styles for reuse.

» Toolbox CSS

Also check out Meyer's resets.  These ensure that browsers have the same defaults for the styles of many elements:

http://meyerweb.com/eric/thoughts/2007/05/01/reset-reloaded/

Google's hartija print style sheet is totally worth a look too:

http://code.google.com/p/hartija/

- and if you find CSS frameworks useful, check out Blueprint et al:

http://webtecker.com/2008/04/17/list-of-css-frameworks/

If you need to roll up  your sleeves and get down and dirty and target browsers, check this out:

http://en.wikipedia.org/wiki/CSS_filter

For choosing fonts:

How many machines have certain fonts? http://www.codestyle.org/css/font-family/sampler-CombinedResults.shtml

Windows/Mac equivalent fonts http://www.ampsoft.net/webdesign-l/WindowsMacFonts.html

Embed fonts: http://www.alistapart.com/articles/cssatten

For working with grids:

column calculator: http://www.29digital.net/grid/

Dean Edwards' script that makes IE behave:

http://code.google.com/p/ie7-js/

Link style generator:

http://www.accessify.com/tools-and-wizards/developer-tools/list-o-matic/default.php?step=1