I used poqbum.com to do mine. It's a little different though. I have a small running pony tiled across the page. But you should be able to set it up that way from that site.
html and css? its not only a myspace thing.... but ok
just find a premade layout and then look through the coding for IMG (images files) and replace one saying background with an image file of your own... from like photobucket.