Once a month or after a special event (e.g. Issaquah Jamboree), you will receive a bill to review for the cost of the referees. To compare the spreadsheet version of the bill with what is online:
Go to Assignor: Manage: Accounting
Set "Club" to your club
Set "Status" to "Billed"
Set "Period" to the appropriate period (e.g. 2011-11 EYSA for November's bill)