i'm not experienced with XHTML or XML? but i found a very good learning source >> W3C XHTML Tutorials i hope that might help
XML is a markup language that's a subset of SGML (Standardized General Markup Language) that allows you to easily create your own languages. XHTML is one of these languages, which is also a reformulation of HTML into XML. XML is often used as a data storage and transfer medium (think meta-data, or data about data), and is best used with XSLT and other XML related technologies. XHTML is a markup language (remember, it's HTML, but served as XML) used to define the structure of a Web page (just like regular HTML). If you're going to be making Web sites, stick with XHTML (or better yet, use HTML 4.01) and avoid XML whenever possible. Also, it's recommended to omit the XML encoding (<?xml version="1.0" encoding="UTF-8"?>) and the content type encoding (application/xhtml+xml) from your Web pages, and using text/html instead since Internet Explorer cannot handle real XHTML and will prompt you to download the file. In other words, use this <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <title>Web Page Title</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <meta http-equiv="imagetoolbar" content="no" /> <meta name="keywords" content="Keywords go here" /> <meta name="description" content="A description of this page goes here." /> </head> <body> </body> </html> Code (markup): You can use ISO-8859-1 instead of UTF-8 but if you do, make sure you save your page WITH that encoding, and most importantly, make absolutely sure that the encoding you use (and save your file as) matches the one sent out by your Web server.