To be clear to completely register you must set up a default credit card with your address attached to it in your BN account. This can be most easily done on your computer.
If you don't have wifi at home and aren't near any wifi (though McDonalds has free wifi), you could try downloading any newly bought books from BN to your computer and sideloading them into your my files folder and then into the books folder on your NOOKcolor.
They should act like any other sideloaded book, but you will still have to have the credit card attached to the account you are using on your nook.
Next time you are in range of wifi that your NOOKcolor can access those ebooks will start downloading to it to the normal area that BN books download to, so you would probably want to go back and delete the ones you sideloaded. Just remember though your bookmarks will not sync between these books so any you will have to make note of the pages you are on for any you are reading.
And yes, you can read your downloaded books without having wifi. You can also turn off the wifi on your NC to save battery time.
When you say you can't get to any menu on it, what do you mean? Is there a black screen or is it the opening screen with the n on it? If it is in sleep mode with the black screen hit the hard n button at the bottom to wake it up and the n screen will come up and then you must drag the little n button that is on the left hand side of the screen all the way to the right-touch it with your finger and drag it across the screen.
If the screen is black and hitting the hard n doesn't wake it up then it is completely off and you have to turn it on first.
"I still believe in spite of everything that people are good at heart." Anne Frank.
