This is the book I have to hand when doing any tricky XML, XSL stuff.
What you get is a quick reference when you need to look up some XSL-T tag or XPath expression you can't remember, or the entity code for a symbol you need. You also get a reference section with Java code examples for SAX and DOM.
When I need more details on XSL I dip in to the XSLT Programmer's Reference, and if I need more details on CSS I'll go to Cascading Style Sheets: The Definitive Guide. But for XLink, XPointers and FO I'll be relying on this nutshell to tell me just enough to get stuff done.
There's no mention of XML schemas, but everything else seems to be covered.
My rating: Recommended