Joseph Tews of the Summit Group gives us some Helpful tips when upgrading Business Portal 4.0 (for GP 10) to Business Portal 5.1 (for GP 2010 and SharePoint 2010)
Helpful tips when upgrading Business Portal 4.0 (for GP 10) to Business Portal 5.1 (for GP 2010 and SharePoint 2010) » Summit Group Software Blog
Microsoft & the GP EcosystemExcel & OfficeTips & Hidden FeaturesGP 2010GP 10
Archived post from 2011. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.