CSS for a full page background image
One of the quickest ways to give style to a webpage is to use a full screen image as its background. It can be done with a surprising little bit of CSS. This code will fill the entire background with a centered and scaled image that doesn't cause scrolling and works in all major browsers.
html {
background: url("http://i.imgur.com/uO3puXn.jpg") no-repeat center center fixed;
-webkit-background-size: cover;
-moz-background-size: cover;
-o-background-size: cover;
background-size: cover;
}