I've built a home server (pretty much just a basic PC with a couple of big HDDs) which I would like to use as an FTP server and a minecraft server. Both would be for members of my gaming community. I would also like to access my home server's terminal while not at home (SSH).
I'm currently unsure of how I'd give out access to the FTP server, but I'd like it to be available to whoever in the community wants access, so it could potentially be somebody hostile, but it wouldn't be random attack-bots. Chances are I'll either send them the login details of a shared 'guest' account or I'd give individual members separate accounts.
I don't plan to host any important or personal data on the server, but I'd like to secure it as much as possible without making it a pain for people to use. It is connected as a node in my home network, and has nothing special about it (other than currently being port forwarded in router for minecraft server).
It is running Ubuntu server 15.10, and is connected to the Sky Hub router via a 5-port unmanaged switch (which my personal desktop PC is also connected to). It has a static internal IP.
Is what I'm planning a terrible idea, and how would I mitigate against potential attacks?