Banners and Making Room

Right now if i put a banner or the right side of the screen there isn't enough space for it. I am not going to be using the banner on the left side of the screen. So is there a way to make more room on the ride side for the banner???

An idea i had was to make the website left justified (or whatever you call it). Right now it is centered (with not enough space on either side for a normal sized banner). But I have no idea to do this. Any ideas??

Any help would be appreciated? Thanks