Some time back one of our friend was asking about HTTP Handlers. Read
the following articles which are very good.
http://msdn.microsoft.com/asp.net/reference/extend/
About IIS and ASP.NET
http://www.theserverside.net/articles/showarticle.tss?id=IIS_ASP
Regards
Manish
www.asp.net
www.dotnetspider.com
www.codeproject.com
www.c-sharpcorner.com
www.gotdotnet.com
www.dotnetbips.com
Regards,
Satheesh