Documentation and Info

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SQL Server Analysis Services
MSDN: SQL Server Analysis Services Books Online
MSDN: SQL Server Analysis Services Tutorials
TechNet: SQL Server 2005 – Analysis Services

SQL Server Integration Services
SQLIS.com - SQL Server Integration Services
MSDN: Integration Services
MSDN Forum: SQL Server Integration Services

SQL Server Database Engine
MSDN: SQL Server Database Engine Books Online
TechNet: SQL Server 2005 – Database Engine

Other
MSDN: SQL Server 2005
MSDN: SQL Server 2005 Books Online
SQL Server 2005 Project REAL
Microsoft BI and PerformancePoint Server
Microsoft Office PerformancePoint Server
The many-to-many revolution by Marco Russo

Oracle
Oracle Database Online Documentation 10g Release 2 (10.2)