Question on Adding a Column for Icons

[Whiterook]

I've searched the board for an answer, but found nothing satisfactory....yet .

There is a thread here with a link posted for a modification/plugin, unfortunately there seems to be some issues with 3.5.4

It would be my guess that the columns can be added to the forums home page using CSS. Although I'm not all that familiar with CSS, I am willing to give it a go (on my test site first of course).
My problem is finding the correct template(s) to edit.
Can someone direct me to the right template(s)?

Here is what I would like to do:

1. Add a column to show different icons for each of the forums found in the various catagories.... (i.e. earth icon for news section... clown icon for the jokes section ect..ect.)

2. Link those icons to it's respective forum.

Thank You in advance.
Respectfully,
WR