Here is a list of tutorials available on the Web. More are being added each week.
Microsoft XML Tutorial
20 Questions on XML
IBM Tutorials: Overview of XML
http://www.software.ibm.com/xml/education/tutorialprog/overview.htm
Writing XML Documents
http://www.software.ibm.com/xml/education/tutorialprog/writing.html
XSL Tutorial
18.218.129.100