You can access your Billing information by going to My Account > Billing & Password. The billing information tab provides your next billing date and provides the ability to change your billing contact information. (see an example)
You can also easily change your credit card information to be used on your next billing date by clicking on the link for "Change your credit card".
Click on the "Invoices" tab to view your invoice history. If you have a past due invoice, you will see a link for "pay now." (see an example)
Click the view icon to view or print the invoice. The view screen shows the details of the invoice including which users are included in the invoice for that month. (see an example)
Click the print icon to print the invoice. (see an example)