After looking at other virtualization packages, I finally settled on VirtualBox. VirtualBox does just about everything that I'm looking for in virtualization software -- not too much as to give me features I don't need, not too little as to leave me lacking. Oh, alright, it doesn't currently let me run 64-bit guest operating systems, but other than that it's really fine.
Here I'll run through a quick VirtualBox installation of a Ubuntu guest. I'll just do it all in screenshots as everything is self-explanatory.