How to sign up without credit card?

Create a NEW account using these instructions. Make sure you follow the instructions. Many do not and if you do not you will not get the None option. You must use an email address that you have not used with Apple before.

Creating an iTunes Store, App Store, iBookstore, and Mac App Store account without a credit card

Go to this website to make apple ID: https://appleid.apple.com/cgi-bin/WebObjects/MyAppleId.woa/

They don't ask for credit card info there.

Yes they do.

select NONE. its a little gray button right next to the credit card icons on the page where they ask you to fill out CC information. see Texas mans explaination in this thread: https://discussions.apple.com/thread/4821217