I had the need to set up an iTunes account the other day for a person who did not have a credit card and was frustrated at the convoluted way of doing this. Sure, there was instrutions on how to do this in the Apple Knowlege Base but it was all to hard at the time.
So what I ended up doing was simply creating a new account using iTunes and using a credit card, then deleting the card by selecting "None" after the account was created.
Simply log back into your account, select view my account from the store drop down, click 'edit' to the right of your credit card number in payment options, then click None.
It's simple and easy, and you don't have to download free apps and do dumb things like that (right).