52331 Urgent, quick code fix

I messed up a simple site by trying to make some changes. The site is in CSS. It was fine until I tried to add a background, which for some reason un-centered the page and made the color disappear in the little bar across the top of the page, under the logo. Also, when I insert a background on the entire page, the logo looks bad, since it's against white. Can someone put my background JUST in the lower sections of the page? The site is 5 pages, so I'd need that for each. But I need it TONIGHT. A person who knows this stuff should be able to do it in 10 minutes. We do Website marketing, but many customers start without Websites and want us to do that too, so I need a roster of regular programmers to use and privately invite. Although we've had great people outside the country, because of project urgency, we also now need people in the U.S., preferably on the east coast (again, due to time).