At Microsoft Technet, you can ow download the updated version (as of July 21 2006) of Books Online for SQL Server 2005.
Download an updated version of Books Online for Microsoft SQL Server 2005, the primary documentation for SQL Server 2005. The July 2006 update to Books Online contains new material and fixes to documentation problems reported by customers after SQL Server 2005 was released. Refer to “New and Updated Books Online Topics” for a list of topics that are new or updated in this version. Topics with significant updates have a Change History table at the bottom of the topic that summarizes the changes.
Books Online includes the following types of information:
Setup and upgrade instructions. Information about new features and backward compatibility. Conceptual descriptions of the technologies and features in SQL Server 2005. Procedural topics describing how to use the various features in SQL Server 2005. Tutorials that guide you through common tasks. Reference documentation for the graphical tools, command prompt utilities, programming languages, and application programming interfaces (APIs) that are supported by SQL Server 2005. Descriptions of the sample databases and applications included with SQL Server 2005.