Open up Fetch, by default the New Connection window opens; if it does not, then click on the File menu at the top of the screen.
Select New Connection ... from the drop-down menu.
Enter the following information:
Host Address: ftp.yourdomain.name (change this to the domain you wish to use).
Username: This will be your FTP username.
Connect using: FTP.
Password: This will be your FTP password.
Click Connect.
N.B. If you are unsure of your username or password, they can be found within the FTP Logins > Manage section of the control panel (http://cp.xcalibre.co.uk).