The handful of links I used (and things I learned) while doing this:

• iTunes is now DRM-Free! What does that mean? It means all the music you buy from iTunes can now be played on any device (capable of playing AAC's, which are widely playable). Not only can they be played, but they can be edited, and cut down, and made into ringtones (you should upgrade your iTunes to iTunes Plus (there's a link over on the right-hand side)).
• Rogue Amoeba's Fission - On my Mac, I found this application to be wonderfully awesome in creating those ringtones. Its ability to edit audio painlessly was exactly what I was looking for. It's a fast and efficient program and I would recommend it for any non-pro audio editing on your Mac.
• Zophar's Domain will get you the sound files to your old Nintendo games. Want the theme song to the fights with Birdo in Super Mario Bros. 2? Bingo. Star power song from Super Mario Bros. 1? sure thing. Very handy site.
• SNESMusic.org - The same type of files, except for all your favorite SNES games instead.
• Learn to convert old school .nsf files to MP3's - Although the narrator comes off as a bit of a jerk, the method worked like a charm (sorry, you'll need a PC to actually complete the steps).
• foobar2000 - Plays all sorts of file formats (on a PC).
• Plugins for foobar2000 to be able to get you what you need. I ended up getting both the foo_gep and foo_adpcm plugins.
• LAME MP3 Encoder - Possibly the best MP3 encoder on a PC, and essential for the aforementioned process.
• If you're trying to play a .rsn file with foobar2000 and it's not playing, try changing that .rsn file's extension to .rar. It worked for me.

Why bother telling you all this stuff, when 99% of you won't care? Because I want to aim for that 1% at times. It took me way too long to figure this out. You would think that somebody like me could do this sort of thing at the drop of a hat… but not knowing that final bullet point easily doubled my time on this project. Anyway, happy listening/converting.