Wordpress as far as I know has a specific theme structure which is one of the things I don't like about it, although it is handy when wanting to change your sites look but no more efficient than a diff
css file would be. I would check their forums for assistance on it. I know they have them and I believe a wiki just for theme creation etc. Good luck man. You will however need to know
XHTML and
CSS to make it all happen.