Change footer background

[blameitonkarma]

I would like to change the background of my footer to an image that closely resembles my header while still maintaining the functionality of the widgets. I have the image ready to go, but I need to know a couple of things:

1. Does the footer need to be a specific size, and if so what are the dimensions? I've looked at the css and footer codes, and I see nothing that clues me in.

2. How, step by step, would I go about changing the footer's appearance from its current solid color to my desired background image?

I'm quite the rookie to Wordpress and to coding in general, so I would sincerely appreciate an answer from anyone who can appreciate my "noviceness" and can patiently guide me through this. Firebug hasn't helped, and I've already searched the forums.

The site is http://www.lauratrojan.com

Your help is greatly appreciated. Thanks.