How do I put a module on the left side?

Hi there, i´m a real newbie when it comes to Hikashop and can´t really get some things to work.

I know how to create modules and stuff like that but I can´t really seem to get them working like I want them to. I want to put a module on the left side of the mail window that has the categories inside it. When you click a categori then you should be placed withing that category in the main window. It should not inherit the styling from the module from the left. Any ideas how to solve that? It can´t be that hard, just me that are kind of stupid.

Cheers,
Anders