Don't you think your question is kind of vague. There are many different FTP packages out there you could be using, like ws-ftp, proftpd and so on.
Have you checked any of the documentation on any of the ftp package of choice sites? Most that I know of don't have a GUI way of configuring unless you install something like Webmin which you can find at www.webmin.com
Members aren't here to write novels and howtos but to give specific answers to more specific questions.. I'd suggest trying to read up more on FTP, which one you will be using then if you get stuck or don't understand, then come and ask away.. but members shouldn't have to repeat what's already out there on the net....
A great place to start looking and searching is www.google.com/linux