buy music Q&A

i wanna use itunes to Buy Music, i know that you can buy those prepaid cards. But i was wondering if i could use those cards WITHOUT giving credit card information? Also, i know it asks for credit card info when you try to make an account with apple, can that be avoided as well?

I am just curious. I Buy Music from the Itunes store.
And as for the teens/preteens that DO buy music. Where do you get the money from?