Here are some interesting resources about SQL Server.

EBooks

SQL Server 2008 Installation (PDF)

Introducing Microsoft SQL Server 2008 (Full ebook – PDF)

SQL Server 2008 CheatSheet (PDF)

Questions and Answers (PDF)

SQL Server 2008 R2 Datasheet (PDF)

Database Development (HTML)

System Views poster (PDF)

Server Monitoring Webinars

Brad’s Sure Guide to SQL Server 2008 (PDF)

SQL Server Execution Plans

Videos

http://www.microsoft.com/sqlserver/2008/en/us/demos.aspx
http://www.sqlservervideos.com/
http://idealprogrammer.com/videos/24-hours-of-sql-server-2008-presented-by-microsoft-experts/
http://www.softwaretrainingtutorials.com/ms-sql-server-2008.php
http://db-management.com/live/