In order to use FTP to upload your content to your domain name, you will probably first want to download an FTP client.  An FTP client is just a program you use to perform the FTP commands for you and has a nice simple interface. 

A free FTP program that is available and good to use is FileZilla.  Download the software from the following project page - http://sourceforge.net/projects/filezilla/

You want to be sure you get the FileZilla latest version download for Windows, and it should be named somehting like this FileZilla_2_2_18_setup.exe.  Do not get the "server edition". 

 Once installed if you launch FileZilla you will have two window panes.  The left side is your computer, the right side is the remote computer you are connecting to.

In the address bar at top use your website URL (www.yourdomain.com).  Enter your userid and password and click quick connect.  

The filesystem on your website server should now be displayed.  Remember to put all files for your website in the "www" folder.