The advantages of using the Scripts class ... jQuery Library, Caching/Compression, remove of inline scripting, Only loads files when needed
Setting a CSS File
To set a CSS file for your plugin you would point the Scripts class to the file like so:
global $_SCRIPTS; $_SCRIPTS->setCSSFile('polls', '/polls/style.css');
As stated before this needs to be done before you run the function COM_SiteHeader or in your plugins plugin_getheadercode_xxxx function. If your plugin has a block or uses Autotags that need the CSS file then you should always make sure it is included since Geeklog has no way of knowing if a block or Autotag will be displayed before the header is written.