Database Mirroring Resources:

SQL Server: Database Mirroring Best Practices and Performance Considerations

Database Mirroring in SQL Server 2005  

SQL Server 2005 Database Mirroring FAQ

SQL Q&A: Server Tuning, Mirroring, Log Shipping and more

SQL Server Storage Engine : Database mirroring questions from TechEd: Failover and partner timeouts. 

How to Configure SQL Server Database Mirroring for use with ODBC applications 

SQL Server Database Mirroring and Windows SharePoint Services 3.0/Microsoft Office SharePoint Server 2007 (Part 1)

SQL Server Database Mirroring and Windows SharePoint Services 3.0/Microsoft Office SharePoint Server 2007 (Part 2)

SQL Server Database Mirroring and Windows SharePoint Services 3.0/Microsoft Office SharePoint Server 2007 (Part 3)

SQL Server 2008 Resources:

Download the latest SQL Server 2008 CTP software

SQL Server 2008 Free E-Learning Courses

Great SQL Server 2008 posts on using spatial data types and FILESTREAM on RDoherty's Blog

SQL Server Tech Center on TechNet

SQL Server Developer Center on MSDN