Office 365 Groups

docs.microsoft.com
Office 365 groups and Microsoft Teams - Link

Microsoft Tech Community -
Office 365 Groups - Link
New Blog Series - Link
Syncing Security Groups with team membership (PowerShell Script) - Link

Support - 
Office 365 Groups - Link

What's new -
Office 365 Groups - Link

End user training - videos
Unite your team with Groups in Outlook - Link

===========================================================

Unofficial Resources - Info, Tips and Tricks

An everyday guide to Office 365 Groups - Link

Blocking Guests from Classified Office 365 Groups (and Teams) - Link

Teams Now Captures Compliance Records for Hybrid and Guest Users - Link

Licensing - Removing the License for an Office 365 Feature with PowerShell - Link

Synchronizing AAD Security Groups with Office 365 Groups - Link