I have successfully learned to convert an AIFF audio file to an mp3. Sometimes, when I decide I am completely computer illiterate, I surprise myself.
I think my best method (so far) has been to load AIFF or WAV or whatever kind of file I have into Audacity, and export it to MP3. (It's not a Save As, it's under Export.) If I recall correctly, you choose MP3 first, and then it lets you choose the bit rate and quality level you want.
I use several programs: one is a wav file editor where I can manipulate files as needed, and another that can break up big wav files into tracks, then another to convert wav files to MP3s. I was given the programs, so that's how I learned to do all that.
