Get this great Red Gate resource for free: The Best of SQL Server Central Vols 5 and 6 and also get this one The Art of High Performance SQL.
If you are not convinced, with this download you can get also this cool ebooks:
|1. Brad's Sure Guide to SQL Server 2008|
|2. Brad McGehee's DBA Best Practices|
|3. How to Become an Exceptional DBA|