When you start PuTTY, you will see a dialog box. This dialog box allows you to control everything PuTTY can do. See chapter 3 for details of all the things you can control.
You don't usually need to change most of the configuration options. To start the simplest kind of session, all you need to do is to enter a few basic parameters.
In the Host Name box, enter the Internet host name of the server you want to connect to. You should have been told this by the provider of your login account.
Now select a login protocol to use, from the Protocol buttons. For a login session, you should select Telnet, Rlogin or SSH. See section 1.2 for a description of the differences between the three protocols, and advice on which one to use. The fourth protocol, Raw, is not used for interactive login sessions; you would usually use this for debugging other Internet services.
When you change the selected protocol, the number in the Port box will change. This is normal: it happens because the various login services are usually provided on different network ports by the server machine. Most servers will use the standard port numbers, so you will not need to change the port setting. If your server provides login services on a non-standard port, your system administrator should have told you which one. (For example, many MUDs run Telnet service on a port other than 23.)
Once you have filled in the Host Name, Protocol, and possibly Port settings, you are ready to connect. Press the Open button at the bottom of the dialog box, and PuTTY will begin trying to connect you to the server.