There are hundreds if not thousands of great resources for learning and continually improving. These are a few of my favorite ones.

Web Sites

Kimball Group http://www.kimballgroup.com
TDWI http://tdwi.org
Information Management http://www.information-management.com
Microsoft BI Resource Center http://www.microsoft.com/bi/resourcecenter/default.aspx
Microsoft BI Product Team Blog http://blogs.msdn.com/oneclickBI
Mobile Business Intelligence http://www.extendedresults.com
Data Visualization http://www.perceptualedge.com
Visio & Visio Services http://blogs.msdn.com/b/visio
Visifire Data Visualization Components http://www.visifire.com
Telling Stories With Data http://data-stories.com/home/
SQL Server 2012 Resource Center http://msdn.microsoft.com/en-us/sqlserver/denali_resource_center.aspx
SQL Server Data Platform http://blogs.technet.com/b/dataplatforminsider
SQL Server Best Practices http://technet.microsoft.com/en-us/sqlserver/bb671430.aspx
SQL Server CAT http://sqlcat.com
SQL Server Performance http://www.sql-server-performance.com
Database Journal http://www.databasejournal.com
SharePoint http://sharepoint.microsoft.com/en-us/Pages/default.aspx
SharePoint Team Blog http://sharepoint.microsoft.com/blog/Pages/default.aspx
Business Connectivty Services http://blogs.msdn.com/b/bcs
SSAS and PowerPivot http://blogs.msdn.com/b/analysisservices
SSAS Info http://ssas-info.com
SSAS CodePlex http://sqlsrvanalysissrvcs.codeplex.com
BIDS Helper http://www.codeplex.com/bidshelper
SSIS Resources http://social.technet.microsoft.com/wiki/contents/articles/776.aspx
Chris Webb Blog http://cwebbbi.wordpress.com
Teo Lachev's Blog http://prologika.com/cs/blogs/default.aspx
Denali and Crescent http://www.microsoft.com/sqlserver/en/us/product-info/future-editions/denali-breakthrough-insight.aspx
PowerPivot http://www.PowerPivot.com
PowerPivot Info http://powerpivot-info.com
PerformancePoint http://blogs.msdn.com/b/performancepoint
Reporting Services http://blogs.msdn.com/b/sqlrsteamblog
SQL Server Data Mining http://www.microsoft.com/sqlserver/2008/en/us/data-mining.aspx
SQL Server Data Mining Resources http://www.sqlserverdatamining.com/ssdm
Weka Open Source Data Mining http://www.cs.waikato.ac.nz/ml/weka
R Statistical Computing http://www.r-project.org
KDD-Nuggets http://www.kdnuggets.com
Electronic Statistics Textbook http://www.statsoft.com/textbook/stathome.html

Books
ACM Online Books and Courses http://www.acm.org
The Data Warehouse Toolkit Collection by Ralph Kimball and Margy Ross
Applied Microsoft Analysis Services 2005 by Teo Lachev
Applied Microsoft SQL Server Reporting Services 2008 by Teo Lachev
Microsoft SQL Server 2005 Integration Services by Kirk Haselden
PowerPivot for Excel 2010 by Marco Russo and Alberto Ferrari
Practical PowerPivot & DAX Formulas for Excel 2010 by Art Tennick
Professional Microsoft PowerPivot for Excel and SharePoint by Sivakumar Harinath
Microsoft SharePoint 2010 PerformancePoint Services Unleashed by Tim Kashani, Ola Ekdahl, Kevin Beto and Rachel Vigier
Data Analysis Using SQL and Excel by Gordon S. Linoff
SQL Server 2008 Internals by Delaney, Randall, Tripp, Cunningham and Nevarez
Excel 2007 for Scientists and Engineers by Gerard Verschuuren
Excel 2007 Advanced Report Development by Timothy Zapawa
Excel 2007 PivotTables and PivotCharts by Paul McFedries
Data Mining: Practical Machine Learning Tools and Techniques by Ian H. Witten and Eibe Frank
Data Preparation for Data Mining by Dorian Pyle
Data Mining with Microsoft SQL Server 2008 by Jamie MacLennan, ZhaoHui Tang, and Bogdan Crivat

Microsoft BI Training Courses and Hands-on-Labs
http://msdn.microsoft.com/en-us/
SQL10R2BYFBI-TrainingCourse

Tech Ed 2011 Presentations
http://channel9.msdn.com/Events/
TechEd/NorthAmerica/2011