Thread:Project:Support desk/How do I define custom tables in a skin's css file?

I would like to predefine custom table formats in the css that various contributors can then use when adding content. I'm new to Mediawiki. Can anyone point me to resources that provide detailed instructions for defining tables, and other elements for that matter, in the skin's css? I am using Mediawiki 1.16.5, PHP 5.3.3, MySQL 5.1.52. Thanks in advance.