The shipping address is where the box itself is going to be mailed. This should be your house.

The billing address is the address on file for that specific credit card, and will be your friend's information if it is his card.

Hey thanks so much for the info guys, but when you state same email, would that be the email on the billing information ?

You can also say that it is a gift.  This allows you to do as above and then get list your email.  This however will also send your friend a confirmation receipt.

Your best bet would be to do the following:

In the billing information, use all of your friend's information, including his/her email address.  The most important pieces of information are his/her street address and zip code.  This way an email will be sent to your friend for record keeping.

In the gift recipient information, enter all of your information, your address (where your package will be sent to) and the email address associated with your Impulse account, if you already have one.  You will receive an email as well confirming that the order has been gifted to you.

If you enter the same email address for gift giver and gift recipient, our system gets confused and uses the wrong shipping information.  A lot of people do this, it makes me crazy. 

Hope that helps!