Itunes Folder Structure

Doing backups this evening, I noticed that it appears I have some remnants
of previous iTunes versions. Specifically,

- in the Music folder, I have an iTunes folder and an iTunes Music folder.
- the iTunes folder also has an iTunes Music folder but it is empty (all
music is in the ~/Music/iTunes Music folder)
- in the iTunes folder, I have iTunes 3 Music Library, iTunes Music Library,
iTunes 4 Music Library

My questions are:

Do I need the old versions of the iTunes x Music Library? Can I delete them?

Since I am now running iTunes 4, should my music be stored in ~/Music/iTunes
Music or ~/Music/iTunes/iTunes Music?

If my music is supposed to be in ~/Music/iTunes/iTunes Music how do I move
all my music to there?

Thanks,
Keith