Hosting an FTP? And a mail server? And a php/sql wiki?
 

I release there's probably a myriad of information on this matter, but it's mixed in with a shiteload of other stuff, namely people flaming linux users :D

I'm using an old PC to set up a mail server for friends, an FTP server and an online wiki for a friend. I'm pretty set on using Mandrake, but don't really know much about it, or about what software is available for it. Indeed, I don't really have much experience with servers at all.

So, what software need I use to host files on an FTP, host mail on my domain and host a wiki?

For ftp, you have just to launch an ftp daemon. You have something like that probably installed, and need only to activate it. Go to the Mandrake Control Center (or just type
drakconf), Go to system, and then DrakXServices.

There, you'll see a bunch of different services you can activate, for example an ftp daemon (all daemon have their name finishing with "d", like proftpd for the one I use).

To install a daemeon from rpm package(if you haven't done that when installing the system) go to MandrakeControl Center->Software-> Add rpm (or just type rpmdrake as superuser), type
ftp in the search area, and look for various ftp daemon it proposes, and choose one.