How add the image to the background Financial Business

I would like use an image in the background of the site instead of the white background. I would like to know which css file I have to change and where to place the image so it shows up behind the logo, navigation and main body.

Thanks again

If you can supply an image and clearly state which part of the template you want image to cover as main template is made up of 3 different parts.

1st part is logo / menu / slider
2nd part is mainbody
3rd part is bottom modules ( black colored ) / footer.

If you want to cover all of them you need to make changes to templates php file. Its simple.

Thanks again. I would like the image to sit behind the logo/menu/slider and site behiond the mainbody as well as the footer modules.

thanks