Following are blogs / forums / official sites which I constantly read, for my betterment:
Microsoft Team:
Developing For Dynamics GP (Microsoft Tech Team)
Inside Microsoft Dynamics GP (Official GP Blog)
Microsoft Dynamics GP Official Product Site
Microsoft Dynamics GP Support Blog
Microsoft Dynamics Connector (ERP with CRM)
Microsoft Dynamics Corporate Performance Management
Microsoft Dynamics CRM Team Blog
Microsoft Dynamics GP Certification Portal
Microsoft Dynamics GP Blogs Syndicated on Microsoft
GP Forums:
MVP Blogs:
About Dynamics, Development & Life (Jivtesh Singh)
DynamicsAccounting.net (Mark Polino)
The Dynamics GP Bloster (Mariano Gomez)
Dynamics Confessor Blogspot (Leslie Vail)
Interesting Findings & Knowledge Sharing (Sivakumar Venkataraman)
GP Community:
Winthrop DC (David Musgrave) Blog
Belinda, The GP CSI (Belinda Allen)
Computeration Dynamics (Gloria J. Braunschweig)
Dynamics Blogger (Janakiram MP)
Dynamics Care GP Blog (I.B.I.S., Inc.)
Dynamics GP Builders & Reporting (Devon Southall)
Dynamics GP Expert Blog (Gilchrist Scott)
Dynamics GP Insights (BKD Technologies)
Dynamics GP Knowledge Share (Sandip Jadhav)
Dynamics GP Land (Christina Phillips)
High Dynamic Range (Aaron Berquist)
In Touch With Dynamics GP (M-HANCE)
Kuntz Consulting GP Blog (Jennifer Kuntz)
MBS Guru (Michael D. Johnson II)
MS Dynamics World GP Resource Center
Real Life Dynamics User (Ron Wilson)
Rose Business Solutions GP Blog
CRM Community:
Dynamics CRM Trick Bag (Richard Knudson)
IT Community:
SharePoint Community:
SharePoint Blog (Laura Rogers)
ERP & Accounting Community:
The Death of Reason (Dwight Specht)
Energized Accounting (Bill Kennedy)
Dynamics GP - Learn & Discuss 