- the name of the server for ftp (or IP address for ftp)
- a username
- a password
website: the public address of your website, eg www.mysite.co.uk
server: the address of the server for ftp purposes or the IP address of the ftp server. This may be the same as your website domain name, or a variation on it such as ftp.mysite.co.uk
username / password: given to you by your host or website provider
initial dir: This is not essential, it may not even be necessary. If you don't give it you'll still be able to browse the server for the page you need. If your pages are in a directory called 'docs' or 'htdocs' or similar, then you can enter it here.
stylesheet: Not essential but if you'd like to be able to edit or view your stylesheet, or make use of classes within it when you insert certain elements, then you'll need to enter its filename here. (relative to the ftp server root - add a directory too if necessary). It'll end '.css'.
If not all of the necessary details are filled in correctly, then the editor should tell you which to check.