How to add a sidebar?

I would like to add a sidebar on the left of my PunBB forum. How can this be achieved? Is there a mod designed for this purpose? If not, what code should I add?

Here is an example of what I want:
http://www.tgforums.co.uk/forum/

You can see here the sidebar on the left. I want such a sidebar, with sections that has the same header as the navigation bar or forum title headers.