Windows: turn on folder options Show hidden folders --> open up my computer and open up your ipod device
look under the hidden folder data and possibly sub folder music then you'll find a bunch of 001 002 etc folders. Each folder has your music in it, but will be named something like LSDI or XLZK etc.
I would just create a new folder on the desk top to put all the ipod files together. Then when you move the desktop folder into itunes, i'd recomend making it an 'ipod playlist' with all your songs just so you can easily go through what was on your ipod -- the names might have gotten messed up so just go through the songs and double check.