Header height and image questions

Hi, I’m developing a site for a customer and am having trouble getting the suggested css code that I’ve found in the forums to work.

I’d like the main header layout to be the first one under header layout – logo to left and menu to right, but I’d like the header height to be 475px.

I also have a background image that I want in the header but have not been able to make thatt happen either. Image is 1240×475.

Any help would be appreciated.
Thanks,
Sandy