http://www.dotnetspider.com/Technology/ (.NET tutorials)

http://winprog.org/tutorial/

http://www.tutorialized.com/

www.mmg.vmei.acad.bg/

http://j-walk.com/ss/excel/index.htm (Excel tutorials)

http://nehe.gamedev.net/ (Game programming tutorials)

http://www.tutorgig.com/t/Excel //Excel tutorials

http://www.math2.org/