Two Column Display lists

Hello

I am looking to make my output on my category pages into to columns

For example

This page

http://plumbingskool.com/lessons

I would like it to be two columns of links instead of one long one,

I am assuming I will have to adjust the files in the inclueds or can this be done within the template?

I did look through codex and could not find the answer , I am really sorry if its posted somewhere.

Any help would be awesome!

Thanks in advance!