tmette

Most people use a gradient or something that they can repeat across the background. They are simple but can provide a nice detail to the page. It also allows for a smaller file-size since your image only has to be so tall/wide and repeat it horizontally/vertically. If you are using an actual image, I would size it so that it fits within a 960px wide screen. This will assure you that people with a low resolution like 1024x768 will be able to still see it.