Microsoft BI TechCenters: Learning and Resources

Apart from subscribing to the blogs and reading the books in the Sites and Blogs and Books sections of this blog you can also visit the following TechCenters on TechNet and MSDN:

SSAS – Multidimensional Data

SSAS – Data Mining

PowerPivot for Excel

You can find a good collection of whitepapers, articles and links to various resources.