It would be a nice idea to center the container for wider browsers, as it sits to the left on mine. (Anyhow, that's a minor point.)
ronpat's point about not setting heights is an important one to heed. The ideal is for your header to contain its contents naturally, and you can do that with things like overflow: hidden or the clearfix method.
Regarding the footer, it's better to associate the background image directly with the element it visually applies to, to avoid overlaps like you get when the text is resized or the browser window adjusted, as ronpat described.