These tutorials are a replacement for asking you to buy a textbook. There are several reasons for this:
You are expected to read at least one tutorial on each subject. This is a course requirement. I reserve the right to ask exam questions on material in the tutorials but not covered in my lectures.
If you would like a textbook, CodeNotes® for XML by Gregory Brill covers many of the topics, and is both excellent and very cheap ($14 at Amazon)..
W3Schools Online Web Tutorials
There are a great many of these tutorials, and most are extremely good. Some are extremely Microsoft-specific, such as the one on DOM, and I do not recommend these. Some have "Try it yourself" links; I have had mixed success using these.
There are fewer of these tutorials than W3Schools, but they are equally good. They are very heavy on examples, so if you like to learn from examples, this site is for you. The namespace tutorial is the best and most thorough that I have found. "XLab," used in some of the tutorials, is an interactive applet that I think is excellent.
Sun's tutorials are usually excellent, and these are no exception. This page contains tutorials for XML, XSLT, SAX and DOM. However, the DOM tutorial assumes that you have already worked through the SAX tutorial, so SAX and DOM should be studied in this order.
These are of more varied quality. Some are very good.