how to transfer all songs from old ipod mini to itunes

I have a first generation ipod shuffle (the really small one about the lenth of my thumb) and wanted to please know how (step by step) to transfer all the songs from my ipod shuffle to my itunes library? Upon connecting my ipod mini to my computer (PC by the way), I can see all of my songs, but they are all grayed out and I cannot even select a track to play. I'm really stuck and any help would be greatly appreciated!! Thanks!!