What can I do to avoid exclamation marks in front of my music on iTunes?

The exclamation mark means that the file no longer exists on your hard drive and can’t be found by iTunes. So highlight the song in your library with the exclamation mark and hit Command + Delete.

@brandi, are you storing your music files on an external drive? and then unplugging/unmounting it?

cough yeah, unless there’s an external drive involved somewhere. :)

Tell iTunes “Keep my music folder organized.” And don’t move or delete files once they’re in there.