Store in XML -> process w/ PHP -> Display in XHTML ?

Summary: I've been looking for a resource (book, website, etc) that will address how to write/store information in XML and deliver it as XHTML (using PHP for the processing), but haven't had much luck. I know a little bit of PHP (just enough to be dangerous, but also to recognize how cool it is) and love the idea of XML. The only drawback to XML at this point is that so few browsers can deal with it. So I'm wondering if there is a way to use PHP to do the transformation. I see there are several XML functions in the PHP manual, but nothing seemed "on point" from my investigation. Thanks for any help. TjL ps -- I know this is 'php-general' but a lot of the conversation here is pretty far over my head. Is there a 'php-newbie' list?