I hope you have some comfort working on the command line. If you don't, then this will be a
hard crash course working on the command line.
Anyway, unplug your monitor and keyboard from your main computer, and plug them into the box you just got. You'll be using them for the Operating System installation, and some of the configuration. When you're done, you can reconnect them back to your main computer.
Get Ubuntu Server, as it's made to be ran as a server OS. Go through the installer as normal. When you are done installing, and the system restarted, configure the server with a static IP address. This old article is still really *really* relevant, and teaches you how to do this (also, use
nano as your editor, unless you want to spend more time learning
vi):
http://www.howtogeek.com/howto/ubuntu/change-ubuntu-server-from-dhcp-to-a-static-ip-address/If I remember correct, Ubuntu Server comes with SSH installed and on by default. If not, read this guide:
https://help.ubuntu.com/10.04/serverguide/C/openssh-server.htmlNow, test your server by disconnecting the keyboard and monitor from the server and plugging them back into your main computer, and SSH into the server. If you're running windows, download a program called
putty to do this. If your on a Mac or another Linux machine, open a terminal and type "ssh [ip address]" If everything went correct, you'll be asked for your username and password you set on the server.
Let me know if you got that far, as I'll help you with setting up the Minecraft server once that's been all done. I want to make sure you at least have that much down before moving on.