Office Open XML examples

http://blogs.msdn.com/brian_jones/archive/tags/Zeyad_2700_s+SDK+Examples/default.aspx

http://social.msdn.microsoft.com/Forums/en-US/oxmlsdk/thread/b88e07f6-c146-4990-8f61-c73ceafa186d

MSDN How do I
http://msdn.microsoft.com/en-us/library/cc850837%28office.14%29.aspx

Open XML format resources center

http://msdn.microsoft.com/en-us/office/bb265236.aspx

Creating pivot table in excel 2007
http://msdn.microsoft.com/en-us/library/dd891207.aspx

Office Developer Community Submitted Content
http://msdn.microsoft.com/en-us/office/cc441428.aspx