This project is based on three projects (pin control via ethernet, led control via ethernet, web server tutorial).
It is designed to control Relay via Arduino and Ethernet Shield.
Users connect the Server as a client with Web then turn on and off the button to control Relay offered on Web page.
For this project, author is offering some references.
They will be helpful and linked below.
For more information such as project code, please refer to the author’s blog.
AUTHOR BLOG : http://nmwilliam.tripod.com/arduinet.html