Resize image on Rollover

I am looking for an easy code to place in an external sheet that, when applied, will resize an image link.

I want it to be in a percentage not a definite amount of pixels, so that whatever picture link I apply it to will be decreased by 90% on rollover.

I am trying to get around coding HTML to swap one image for another on mouseover. I just want one image that can be resized.

something like: on mouseover resize image 90%, but in sweet-sweet css lingo.

Here is the initial page I am trying to get it to work for:
http://shrewmusic.com/pages/art.shtml

Thanks for the help and for not slamming me for my ignorance!
Peace.