website control arduno

How can I control arduino pin and get analoge read from my website
What I need to that ?
And how can I setup Ethernet to do that ?

We do this all the time. Normally we use a PHP script on our website. The arduino has an ethernet shield attached and goes out to the web and hits that PHP on your server. You can have the ardunio send data to the server or capture data from the server - or both. You can then have that data stored in a database on the server or you can collect data with the arduino and store it in an SD card (many ethernet shields now come with SD readers/writers.)
Finally you have can the arduino send you an email either on it's own (harder) or by having it hit a php on your server(easier). The arduino sends the the information for the email but the php actually does the sending.

The ethernet set up is quite easy. you need an ethernet shield and you need the Ethernet library in your arduino IDE that matches the kind of shield you get. (most 5100 chip shields work with the Ethernet library that comes with the arduino IDE, but there are other libs for 5200, 5500 and other chips)

here's a good starter

But to help more you will have to describe what you are trying to do.

Check out the GET and POST tutorials - GET and POST Tutorial that will give you an idea how to communicate between your Arduino and a server using either GET (the easiest but less secure) or POST Recognize when you are working with your Arduino etc, the term "localhost" in the various examples you find refers to the computer that the command is running on - it is a special networking hostname that refers to "self" and will not work if you are trying to talk to a different computer - for that you must use a valid hostname or IP address.