How to use sprite sheets?

[40wattstudio]

Between the two of you I think I have a general idea of what I need to do. I'll give it a go in the morning and see what happens. I've never tried referencing a segment of a png file, it's always been an all or nothing sorta thing. But if it works it'll be pretty cool because, loaded as individual images, the file size is 2.5MB (which isn't too bad, really), but the sprite sheet condenses it down to about 1.5MB.
Thanks for your help, I'll let you know how it turns out!