Space for banner/ads

Hi..

I’m really a noob in this coding-game, so i really need some help here.
I wondered if it’s possible for me, to add some banner space in my websites sides.

http://www.poplish.dk

I’d like to have them in the grey area, and where it stay in the middle when you’re scrolling up/down.

Hope you understand what i mean. ?

Regards