Tips & Tricks for my first actual server

I have recently decided to try and build a game server for games like Team Fortress 2 and Minecraft, maybe more.

I have a PowerEdge R710 that I got from an uncle, and all i'm missing are the proper hard drives - which I think I know what to get.

I am new to the world of servers and am not exactly sure how to set this up, but would like to learn. 

What things would i need to do/enable/configure, and what would the best practices for maintaining this server be?