CSS-Tricks. CSS3 . Info - All you ever needed to know about CSS3. Documentation. Spritely is a simple plugin with only two key methods, sprite() and pan() both of which simply animate the background-image css property of an element.
The difference between the two is that a 'sprite' image contains two or more 'frames' of animation, whereas a 'pan' image contains a continuous image which pans left or right and then repeats. Typically, in either case, you would use a png file (with or without transparency) for this. You might wish to use a transparent gif for Internet Explorer 6, though it probably won't look as good. Simple CSS3 framework for creating GitHub style button links.