Nick... have you heard about FireFox add-on "Web Developers Toolkit"?

This is a very useful addon to firefox that will allow you to analyse a webpage off-line.

One of its many features is the capability to view a page's style classes and ID's against any displayed page element.

You'll very quickly see what elements are governed by what style ID's and classes.

Then you can make off-line changes to the css too, to see how they will show up, before you commit them to the live stylesheet.

go to mozilla website and get firefox and the web developer toolkit add-on.