Microsoft Planning Scenarios

http://www.microsoft.com/download/en/details.aspx?id=19191

SQL Server Technical Articles

If you work with Microsoft's BI stack, these articles can be very useful.
SQL Server Best Practices
SQLCAT Articles
Analysis Services 2008 R2 Performance Guide

Microsoft Enterprise Architecture

Here you'll find technical content, news, and community resources covering enterprise, application, and systems architecture.

Microsoft Application Architecture Guide, 2nd Edition

I highly recommend the Microsoft Application Architecture Guide, 2nd Edition for developing solutions using the Microsoft platform and the .NET Framework.

BI Architecture and Design Guide

BI Architecture and Design Guide.

Regular Expressions Resources

Regular-Expressions.info - the premier website about Regular Expressions.
www.regexlib.com - the regular expressions library and a good collection of regular expresions related tools and books from around the internet.

Microsoft SQL Server Webcasts & Events

Microsoft SQL Server TechNet On-Demand Webcasts (English)
Microsoft SQL Server MSDN On-Demand Webcasts (English)

Microsoft SQL Server Webcasts & Events (German)

Documentation and Info

SQL Server Home
Microsoft SQL Server 2005 Home
Microsoft SQL Server 2008 Home

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)