>I’ve come to think of XPath as the language that anybody working with XML shouldn’t be with out. Along with XSLT 1.0, XSLT 2.0, and XQuery 1.0, these are tools that everybody that works with XML should have familiarity with. However, there are still a vast number of people that work with XML that have no idea on what XPath is, and how it can benefit them.
If you are one of these people, and don’t want to spend money on a book, you can get one for free. XPath and XPointer is available free from the O’Reilly Commons website. The nice thing about the book is that it covers XPath 1.0 as well as XPath 2.0. For those getting started with XSL and XQuery, understanding XPath is a must.