Please have a look at four new Best Practices Articles

SQL Server 2005 Predeployment I/O best practices http://www.microsoft.com/technet/prodtechnol/sql/bestpractice/pdpliobp.mspx                                by SQLISVPM team member Mike Ruthruff

SQL Server 2005 Deployment Guidance for Web Hosting Environments
http://www.microsoft.com/technet/prodtechnol/sql/bestpractice/SQL2005DGWHE.mspx
by Alex DeNeui

Resolving Common Connectivity Issues in SQL Server 2005 Analysis Services Connectivity Scenarios
http://www.microsoft.com/technet/prodtechnol/sql/bestpractice/CISQL2005ASCS.mspx
by Carl Rabeler

Implementing Application Failover with Database Mirroring
http://www.microsoft.com/technet/prodtechnol/sql/bestpractice/implappfailover.mspx
by Michael Thomassy, Sanjay Mishra