SharePoint

docs.microsoft.com
SharePoint - Link

Microsoft Tech Community -
SharePoint - Link

support.microsoft.com
SharePoint - Link

Official Blogs -
SharePoint - Link

products.office.com
SharePoint - Link

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Unofficial Resources - Info, Tips and Tricks

Unofficial Blog - Link - (icansharepoint.com)

So, what is SharePoint - Link

An introduction to SharePoint surveys - Link

Infographic - The document circle of life in Office 365 - Link
Tips on what and where to share

An everyday guide to Office 365 Groups - Link

How to create a My Documents view in a SharePoint library - Link

Beginner's guide to SharePoint metadata - Link

How to search in SharePoint - Link

Infographic - The basics of SharePoint document libraries - Link

Practical guide to SharePoint site permissions - Link

How to share externally with SharePoint Online - Link

Infographic - File type and naming restrictions - Link

The absolute basics of version history - Link

What it was really like migrating to SharePoint Online - Link