I'm not in the US, so probably wouldn't be able to follow through with registering billing/delivery addresses, but I was able to register an email address by following these steps:
Once you've clicked on the link in the verification email, you can then login by clicking on the head and shoulders avatar again.
At which point, you get presented with this page, where you can add your other details.
Once you've clicked on the link in the verification email, you can then login by clicking on the head and shoulders avatar again.
At which point, you get presented with this page, where you can add your other details.
