To purchase music, videos, and audiobooks from the iTunes Store, youll need an account. You can use your .Mac account or an Apple ID your created for the Apple Store, or you can set up a new Apple Account. All you need is a valid email address to get started.
Click Account to update your address, use a different credit card, view your purchase history, or make changes to your account information. You can also click the links under Account to buy or redeem gift certificates, and to set up an iTunes allowance.
The Apple ID you set up in iTunes can also be used in iPhoto to order prints and at the Apple Store to purchase Apple products online. For .Mac members, your Apple ID is also your .Mac membership ID. You only have to remember one password to use all the Apple services you want.
iTunes Store
Find Music on the iTunes Store
Find Videos on the iTunes Store
Find Audiobooks on the iTunes Store