SQL BI Microsoft MSDN
Here is some materials for your reference.
Entrance: http://msdn.microsoft.com/en-us/sqlserver/default.aspx
For SSIS: http://msdn.microsoft.com/en-US/library/ms167031(v=SQL.100).aspx
For SSRS: http://msdn.microsoft.com/en-US/library/bb522859(v=SQL.100).aspx
For SSAS Multidimensional: http://msdn.microsoft.com/en-us/library/ms170208(v=SQL.100).aspx
For SSAS Data Mining: http://technet.microsoft.com/en-us/library/ms167167(v=SQL.100).aspx