The sound quality was great by the way. I hope cutting it down doesn't lose too much.
Matt, you mentioned that you didn't know the limitations of buying music from iTunes. When you buy a song from iTunes, you get it in an encrypted file format that only Apple-brand players (including iTunes itself and iPods) can decode.
Other MP3 players cannot decode these files. They're encrypted with their Digital Rights Management (DRM), because the recording industry won't allow Apple to distribute without some kind of DRM. Apple has said that they would love to distribute unencrypted files, but they can't.
Microsoft has its own DRM encryption scheme, which many non-Apple players support, but as far as I know, no players can decode both kinds of files. iPods can't decrypt Microsoft's DRM, and non-iPods can't decrypt Apple's.
If you buy a song from iTunes, you can play it on that computer, plus your iPods, plus up to four more computers which you give access to. If you are going to get rid of a computer, you need to de-register it so that it won't count against your five total. Remember to do that before your hard drive fails!
And now, what if you'd really like your new iTunes song in unencoded MP3 format? You can use iTunes to burn it to a standard audio CD, then you can stick that CD right back in your computer, and rip the audio files to MP3s. iTunes makes that fairly easy, since it handily remembers the song names. But it's a PITA to do frequently, and there is some small loss of sound quality by re-encoding it with a lossy compression scheme.