Apple tell you that once the songs are inside iPod that you can't get them out. BUT!, there are 3rd party programs out there that can do this. I'm not sure which ones are available for windows, but for mac, Ollie's iPod Extractor, PodWorks, ... there's at least 3 for the mac. And there will be some for windows also. See the following link for links to the iPod forum where you'll find info & links, & for your other issue:
How to transfer music to my iPod (& iTunes) To add them to your or your friend's iPod then you'll need to add them to iTunes 1st! I'd then recommend you add them manually! See the Apple iPod tutorial from the last link to see how to do this.
For windows a quick google picked up these: 1.
iPod Access for Windows (Shareware), or 2.
Broken Helix 1.0 - FREE DOWNLOAD, or
3.
a Selection, or 4.
Xpod (Free), or 5.
vPod (Free), or 6.
PodUtil (Shareware), or 7.
iPod Browser (Free), or
8.
iPod Music Liberator (Shareware), or 9.
How to copy music from iPod to computer & iTunes using Tansee iPod transfer (TrialWare)
BTW iPod extraction can be a relatively slow process! (You can find more info on the iPod forum!)