Normally in css, you will define things with a particular id using #(id) and a class is .(classname)
The pseudo class allows you to define particular behaviour, for example, if you want something to change appearence when you hover over it you would use :hover
So, to combine them, if you want everything with a particular class to look a particular way when you hover on it, you might want to try .(classname):hover
However, this does not always work (in Firefox), as I found out five minutes ago.
I was dealing with divs, and the solution was to say div.(classname):hover
So, when using pseudo classes, in order to make sure things work, try to be as precise as possible - (tagname).(classname):(pseudoclass)
However, I subsequently discovered that the hover pseudo class is only valid for links ("a" tags) in IE.
In order ot make them behave like divs, make the use display:block, and if you really want to, remove the href.