Armanino Consulting points us to the Checklists for 2010 year-end processes in Microsoft Dynamics GP available on Customersource.
Checklists for 2010 year-end processes in Microsoft Dynamics GP
Payables & ReceivablesYear-End & 1099
Archived post from 2010. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.