I will be using my sister's credit card to purchase my macbook. do I need her with me to use her credit card? she goes home late from work so I'm hoping I'll be able to use her credit card without her having to go with me.
Now if your sister was real nice, she could add you as an authorized user and then you would receive a card in your name, but her account.
However, I would then promptly advise her against that since she would still be liable for all your charges. Plus then there are issues with age and whatnot if you are under the age of majority to enter into contracts.
If you do use a credit (for anything not just MB) pay it off ASAP that way you dont incur the interest charges. I pay mine off every month. Just bought a MB on mine, got paid 2 weeks later used half of previous month wage and half of this months to pay off the card. Nice new MB no interest charges.