This is the OGC's official documentation, it has several typos but the content is very clear and well documented; very useful to prepare your ITIL Foundation Certificate - it might be wise to wait the new edition of ITIL V3.0 that will cover other ITSM topics

All the best,
Christophe Poizat
(...)

This is the official guide to service support, covering:

(1) Service Desk
(2) Incident Management
(3) Problem Management
(4) Configuration Management
(5) Change Management
(6) Release Management

Recommended if you are pursuing ITIL certification because this is the official guide, or wish to invest in reference material for a shared library when implementing ITIL. The service delivery topic is well covered from theory and practical perspectives, and the interrelationship between and among process areas are clearly depicted.

If you are merely exploring the benefits of the ITIL or want a condensed reference I recommend instead that you look at "IT Service Management: An Introduction" (ISBN 9080671347), which covers the six service support processes in sufficient detail to gain a solid understanding of them and what implementing them entails. Another resource I highly recommend is ITIL Community Forum, which you can reach by pasting the ASIN number B0002FP9PO into the search box on this page, selecting all products and clicking GO. This site has a link to an open source version of the ITIL documentation that is evolving, but contains good descriptions of many of the key process areas.