okay. you're first step should really be to make sure its secure. You don't want to set it all up and have to reformat right?
Start by making sure all unnessary services are off (apache, telnet, cups, etc). Next make sure you have the latest version of ssh and whatever ftp server you want. Maybe do a port scan on the machine the results should look something like this.
Starting nmap 3.30 ( http://www.insecure.org/nmap/ ) at 2004-01-05 11:05 MST
Interesting ports on somedomain (xxx.xxx.xxx.xxx):
(The 1635 ports scanned but not shown below are in state: closed)
Port State Service
21/tcp open ftp
22/tcp open ssh
that is assuming its a pure ftp server, but that would be a good start.
I know in redhat typing setup in a terminal will give you an easy way to choose what services startup on boot, but I'm not sure if mandrake has anything like that. Maybe someone with a little more Mandrake exp can shed some light on that?
If you tell us what ftp server you plan to use I'm sure we can give you some specifics on how to set it up