And the cool settings to use are 128 AAC and 160 MP3.
Just a thought: I ripped all my cd's before purchasing my iRiver, then had to redo the whole project because I wasn't satisfied with the quality of my files. If you can, you might want to try ripping a couple of your favorite tracks at a variety of settings, then listen to those tracks on a friend's player (ideally through the earphones you plan to use), until you've determined the settings that will best suit your needs.
(I'm now facing doing this all over again, as I contemplate migration from a player that supports vorbis, but not audible.com, to one that supports audible but not vorbis. Argh!)