Louis Davidson (Dr. SQL) has a great book on the subject, but he also posted a great shorter version on simple-talk. Always a good reminder for us all...http://www.simple-talk.com/sql/database-administration/ten-common-database-design-mistakes/
Lookup tables or Entiry-Attribute-Value (EAV) tables are often used in SQL programming. Joe as always gives some great advice on how to properly design these kind of tables. http://www.simple-talk.com/sql/t-sql-programming/avoiding-the-eav-of-destruction/ His use of a view to prevent SQL engine from intent locking is a great idea that is new to me, I will have to remember that one.
The guys over at less than dot have a great top 10 SQL Server functions you should know, that you probably have ignored until now (if you read it). http://wiki.lessthandot.com/index.php/Ten_SQL_Server_Functions_That_You_Have_Ignored_Until_Now
SQL 2008 has some new DBA focused features, one of which is the Central Management Server for issuing multi-queries (queries against many servers at once, even down level clients) and Policy Based Management. Connections use your Windows Authentication only.
There seems to be a lot of mis-understanding of log file management, potentially enough to cause data loss in a disaster recovery scenario. Paul Randal has an excellent blog post on the subject and survey results of what the public does: http://www.sqlskills.com/BLOGS/PAUL/post/Importance-of-proper-transaction-log-size-management.aspx
I am currently working on building out a new SAN (older HP EVA 8000) for new Windows 2008 and SQL 2008 migration from SQL 2005. There is so much you can tweak that I wanted to put all my thoughts in one location, so here is my brain dump which will be updated as time goes on. Listed below in order of importance.
I came across some nice TCP port query tools that do better testing than DOS telnet to port x and leave a hanging connection from Microsoft.