I make it a point to visit these on a regular basis. it helps you to be informed. you don’t have to memorize everything, these are just serious readouts, to go figure when the time comes.

www.sqlskills.com (Paul S. Randal and Kimberly L. Tripp)
www.sqlblog.com (Most MVP’s and Good information Blog)
www.sqlservercentral.com (Good Forums Site for SQL Server)
www.sqlteam.com (Good SQL Server Forums)
http://technet.microsoft.com/en-us/sqlserver/default.aspx (for Latest SQL Server Product Happenings)

http://blogs.msdn.com/psssql/default.aspx (Must Visit Weekly)
http://blogs.msdn.com/sqlcat/default.aspx (Must Visit Weekly)

http://social.msdn.microsoft.com/Forums/en-US/sqldatabaseengine/threads (SQL Server Database Engine Forums.. you learn a lot here)

http://blogs.msdn.com/sqlsecurity/default.aspx (Must Visit Weekly)
http://blogs.msdn.com/sqlserverstorageengine/default.aspx (Must Must Visit all Times)
Also check out the TEMPDB Troubleshooting by Sunil Agarwal here http://blogs.msdn.com/sqlserverstorageengine/archive/tags/TempDB/default.aspx (A must must read)

Also in the Tag section there are DBCC Tags.. must read too.. which are by PAUL RANDAL.

Yes and foremost as rule subscribe to WWW.MSSQLTIPS.COM .. it is a good source of SQL Server Daily Dose..