After you log in, click the 'Billing' menu option on the top navigation bar. The most current bill and any past due amount will be at the top of the page. For help understanding your billing statement, you can click Explain my bill.
The 'Payment History' and 'Billing History' sections are on the same page. You can view recent payments in the 'Payment History' section and a complete list of payments made by clicking on 'View All Payments.'