开源Excel操作类库

1.myxls

http://sourceforge.net/projects/myxls/
http://sourceforge.net/projects/myxls/files/MyXls%20Silverlight/MyXls%20Silverlight%20Library/MyXls.SL2.dll.zip/download

2.NPOI
http://npoi.codeplex.com/
http://npoi.codeplex.com/documentation
http://npoi.codeplex.com/releases/view/19351
http://code.google.com/p/npoi/

示例资料
http://msdn.microsoft.com/zh-tw/ee818993.aspx