Start PC music Server from Scratch

I would like to build a music server form scratch using a Mac Mini as my base computer. I'm new to all of this and feel this is a more stable way to go. Of course I will be modifying this base computer a lot, adding RAM ,battery power, external Hard Drives and any other good advise I get. This system is for my office area and I will be right in front of the music server. Can anybody give me some basic advice on how to proceed? I'm starting form scratch and will be buying my mac mini tomorrow. Any advise before proceeding? I'd appreciate it very much.