Prevent your application from DOS attacks

http://omaralzabir.com/prevent_denial_of_service__dos__attacks_in_your_web_application/

http://www.free-ebooks-download.org/

http://css-tricks.com/downloads/

Paypal integration with ASP.NET. A grate article ......

http://www.codeproject.com/KB/aspnet/paypal_c_aspnet.aspx