Beginning XSLT: Jeni Tennison, Apress (£34 Amazon)

Beginning XSLT 2.0: From Novice to Professional (£35 Amazon)

Good introductions

XSLT: Doug Tidwell, O'Reilly (£23 Amazon)

More a Reference Manual, 2.0 Version July 2008

XSLT 2.0 and XPath 2.0 Programmer's Reference (£22 Amazon)

Michael Kay is the XSLT 2.0 Editor so this is authoritative, previously available as two separate books

XSLT Cookbook: Sal Mangano O'Reilly (£27)

Lot of worked examples. New edition covers XSLT 2.0

XSLT Quickly: Bob DuCharme, Manning

Best Introduction (www.manning.com/ducharme)

XSLT and XPath on the Edge: Jeni Tennison, Hungry Minds

Best Advanced Features (£17 Amazon)

Look at Jeni Tennison's site for some good tutorials (http://www.jenitennison.com/xslt/)

MSXML FAQ: http://www.netcrucible.com/xslt/msxml-faq.htm