The key to the ITUNES GIFT CARD $5 will be displayed on your screen immediately after payment, and will also be delivered to your e-mail address that was specified during the purchase.
iTunes Gift Card $5 - This key is intended for US accounts. It is not suitable for any others!
If you don´t have an iTunes account, you can create one when you activate the card.
Instructions for creating an iTunes account: http://support.apple.com/kb/HT2534?