Whenever you activate your account, your 30 days of free Game Time will begin. When using a credit card, ELV or Paypal, you will not be billed for your second month of play until your 30 days of free Game Time is complete. You may cancel your subscription at any time in your first 30 days of play. Your unused Game Time will still be available on your account and you can still play until this expires.
The bold, underlined part seems untrue. When I signed up for billing (I chose the 6 month plan), my card was charged immediately.