- Improving code readability with CSS Styleguides
- CSS Specificity (say that quickly, 10 times in a row!)
Also, Antonio Lupetti has put together some great info on how to organise CSS, here and here.
There is also this older article that has good info/advice on a wide range of CSS-related matters.
If you have any info on any of the above, please enter it in this entry's comments
ps: Comments and/or links to this article are most welcome!