Forum Category Header Graphic?

[DevinM]

I have a jpg image id like to use as a forum category image, where do I edit that at? Everything I edit seems to be incorrect.

This image is my site and in red what id like to change:

http://www.gridironjunkies.net/images/misc/ggcategory.bmp

This is an example site and what it is I am trying to achieve:

http://www.gridironjunkies.net/images/misc/hhcategory.bmp

Any help is apprecated!