Transform Old Computer Into Server

[vex390]

I have this old dual core Dell desktop sitting on my floor. I need a project really bad right now.

I read up on some DIY computer to server articles, but no single one tickled all of my fancies. I'm looking for a system to:
1. Host Files (possibly stream?)
2. Allow me onto my home computer from outside of my network
3. Whatever else would be fun to do that anyone can recommend.

I am not that savvy with servers. I'm studying Information Systems in college but I haven't actually taken any classes about networking or hosting or anything like that yet.

I'm aware of the security risks but I'm not exactly running a business through it.

Here's the det's: I am thinking Linux (maybe something else is better?) since it's kind of all-purpose. I'm stuck behind a spotty router with 5 room mates. I put DD-WRT firmware on the router but it crashes every once in a while.

So my questions are:

What software should I use?
How should I set up my server around a general purpose router?
Since I'm lazy and don't want to memorize my ip address, would there be any reason not to get a domain name or a domain redirect?

Thanks guys!

 

[Bejusek]

Install ubuntu, configure it as a router https://help.ubuntu.com/community/Router. Use your old router as a switch behind your ubuntu machine (so your network looks like: Internet --> Ubuntu server --> Switch ---> Clients). You can register a free domain pointing to your IP address or if it's dynamic use somethig like dyndns.

This way your possiblities are infinite, you can setup anything you want: samba, dlna for streaming, http, ftp, mail server etc.