Help with usergroup image

[UrGonnaDie]

Hello im looking to figure out how to add a image for rank to my site but dont know how to make it work. Here is a link to show what it currently looks like when someone posts. (http://imageshack.us/photo/my-images/705/profilerl.jpg/) and im looking to add this image here (http://imageshack.us/photo/my-images/824/thadmin.png/)

Currently in the HTML Markup i have this (<img src="images/misc/xbox-icon.png" />&nbsp;<span style="color: #C11B17;">) so that it will add the small image to the left of the name and color the users name. Id like to know how to add 1 or more of them images from above to the userclasses so they show when people post.