Yes you can. When you enter the iTunes store, go to QUICK LINKS and click the 'redeem' option, then type the 16-digit code printed on the back of your iTunes gift card and iTunes program will create a new account for you.
YES. You need an itunes acount.
No, you can only redeem an iTunes gift card to one account
When you open up the window for the homepage of the iTunes store, log in if you're not already. As soon as that is done, your current balance should show up in a box next to your email address (which doubles as your account name). Usually, if you have not redeemed a giftcard, your balance will read "$0.00."
yes
no
It's on the back... you have to scratch some stuff off and there it is!!
There is no need to switch anything in your account at all. iTunes keeps a running total of all money credited to one's account from gift cards. Simply input the new card's code and its value will be added to the current account's store credit.
You have to buy one first.
16
Ebay
If you email apple they will probably be able to help apple.com/support/itunes/contact.html?form=account&topic=iTunes%20Store%20Account%20and%20Billing&subtopic=Managing%20your%20Account
yes go to itunes to redeem it