The CiviCRM user and administrator book is a guide for users and administrators of CiviCRM. It covers everything that normal users and administrators of CiviCRM need to know to work with CiviCRM on a day to day basis. The guide covers all functionality that is available via CiviCRM’s user interface.

You can view online of download the PDF version here:

http://book.civicrm.org/user/