Yes you do. You can pay via a credit card, or a gift card that you might be able to buy in some local hardware retailers or supermarkets.
You do have to pay for Itunes songs. They range currently depending on the song from 69 cents, 99 cents, and 1.29 off of itunes. There are alternate ways of getting music for your ipod just email me...
Yes you do but you will have to sinc your Ipod to your computer if you buy a song through the computer.
Yes you do.
You have an account in iTunes Store, and the downloaded song/album gets charged to your credit card.