From Inside Microsoft Dynamics GP: Microsoft Dynamics GP 2013 Service Pack 1 Now Available: What’s Next?
Microsoft Dynamics GP 2013 Service Pack 1 Now Available: What’s Next? – Inside Microsoft Dynamics GP – Site Home – MSDN Blogs
Install, Upgrade & AdminMicrosoft & the GP EcosystemGP 2013
Archived post from 2013. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.