XSL: I like Khun Yee Fung's "XSLT" book, it has good explanations and aimed at an average XML developer without Masters in Computer Science. (Ajith may recommend another book
) Now there are many other available, O'Reilly usually has good books.
DOM/SAX - people say good words about "Java and XML" by Brett McLaughlin, but here
you should listen to somebody with more extensive parsing experience.
What do you mean by "Template documentation"?