Ebook: XSLT Programmer's Reference 2nd Edition

I'm biased towards this book vs. newer editions, since I [like many of us] am still forced to use a XSLT 1.0 implementation.

For that, this book is the bible. It covers, in great detail, examples of just about everything you can do in XSLT/XPath 1.0. Because Mr. Kay wrote the Saxon processor, he can give insights into what an XSLT processor will actually be doing. This sort of information is vital when you want to write advanced XSLT transformations.

This probably isn't the book for the a beginner, but everyone else who programs XSLT 1.0 MUST have this book on their shelves.