how to setup content on a static frontpage with css and xhtml

I would set up a new page template (see http://codex.wordpress.org/Pages#Creating_Your_Own_Page_Templates), create a new page (Pages > New) and set it to use that template, and then set WordPress to use that page as the homepage (Settings > Reading). Then you can fill the custom page template with whatever content you want in between wp_head() and wp_footer().