A great many XML resources are available to you online. Because it's very important to know about them to get a solid background in XML, I'm going to list them here.
The XML specification is defined by the World Wide Web Consortium (W3C), and that's where you should start looking for XML resources. Here's a good starter list (we'll see all these topics in this book):
www.w3c.org/xml— The World Wide Web Consortium's main XML site, the starting point for all things XML.
www.w3.org/XML/1999/XML-in-10-points— ”XML in 10 Points” (actually only seven), an XML overview.
www.w3.org/TR/REC-xml— The official W3C recommendation for XML 1.0, the current (and only) version. It won't be easy to read, however—that's what this book is all about, ...