The launch windows is open for Dynamics GP 2016. As we build toward launch, Microsoft is starting a series of posts building to GP 2016’s release. The GP team just released the Microsoft Dynamics GP 2016 Upgrade Blog Series Schedule!!
Microsoft Dynamics GP 2016 Upgrade Blog Series Schedule!! – Microsoft Dynamics GP Community
Microsoft & the GP EcosystemInstall, Upgrade & AdminGP 2016
Archived post from 2016. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.