Quickly Setting Up and Securing an Ubuntu Server

I'm setting up an old desktop as a server at school. I was going to post details about it later, but after seeing this article claiming that there are hundreds of thousands of unsecured databases out there, I thought I'd go ahead and post some of the basics on installing and securing a server running Ubuntu Linux (7.10 "Gutsy" version).

I'm assuming Ubuntu is already installed. In my case, the desktop version (not the server version which already has most of this pre-installed). I want to quickly convert it to a server to use for some research.

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