I actually have a need on one of my websites for XML. I need to set up an amazon store that feeds from them and there is a package that uses XML that someone else developed that is available but it looks like it would take half my life to set it up. Plus I would like to feed other vendors into this same shop. I also need to feed news to our community...particularly news that effects women and women's issues. I'm thinking XML is the way to go on this too.
Where is a good place to start with this? Currently everything is HTML4.01, CSS, PHP and Mysql on our site. That is where my experience is. Is there a good community that exchanges information on XML that a newbie can adjust into? Is there a particular book that anyone else has found useful? Any articles?
I've about gone blind and am starting to resemble a geek after hanging out on the W3C website

I now need interaction with real people
So please if you have any good resources that you have found helpful in learning and using XML, please let me know.
I apologize if I am saying XML and meaning XHTML ... still not totally sure of the difference. TIA.