The support team has coverage of Microsoft Dynamics GP Year End Release 2013: Analytical Accounting Year End Close
Microsoft Dynamics GP Year End Release 2013: Analytical Accounting Year End Close – Dynamics GP Support and Services Blog – Microsoft Dynamics GP – Microsoft Dynamics Community
General Ledger & FinancialsYear-End & 1099Microsoft & the GP Ecosystem
Archived post from 2013. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.