If you don't want to use any apps all you need to do to add your fav mp3 to you Ringtone, Notification and alarm sound list is.
1) Mount you Droid to you computer
2) In the root folder make media folder
3) in the media folder make and audio folder
4) make a ringtones, notifications, and alarms
Most mp3 show up of the bat.(once you unmount) If they do not try taking out the spaces in the name
Also anything put in the audio folder will showup in the music player.