As an editor, you may or may not deal with a music cue sheet. Usually your music supervisor will help you out with this, but on lower budget shows where you may use stock music or tracks from an online music library, you have no one to turn to. Take a look at this music cue sheet from ASCAP. You can download the excel file model they have and use it on your own productions.
You can also find the link here: http://www.ascap.com/musicbiz/cue%5Fsheet%5Fcorner/