In Firefly, you specified a music library location.
Have you copied the iTunes library file to that location?
The XML file is the one you're after.
2 x M2000's
Infrant ReadyNAS NV+ with Firefly svn-1676
NSLU2, 500GB Maxtor One Touch III, uNSLUng 6.8, Firefly svn-1696
music library in FLAC format