Migrate iTunes Library *with* meta-data to a new machine

In order to bring your music to the default folders, do this:

On your existing machine, go to File -> Library -> Organize Library... and choose Consolidate files. This will copy all of your music to ~/Music/iTunes/iTunes Music in your Home directory.

The metadata is all stored inside ~/Music/iTunes/iTunes Music Library.xml

The most seamless way I can envision this is just by replacing the ~/Music/iTunes folder on your new machine with the one from your old one. Then you'll be getting all of your music, which should now be in ~/Music/iTunes/iTunes Music as well as the metadata in ~/Music/iTunes/iTunes Music Library.xml