Janakiram M.P. looks at ISV participation in Microsoft Dynamics Community. I have a couple of thoughts on this as well but I was saving them for an MSDynamicsWorld column so you’ll have to wait a little bit.
DynamicsBlogger: ISV participation in Microsoft Dynamics Community
Archived post from 2011. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.