Microsoft Virtual Academy
https://mva.microsoft.com/
https://mva.microsoft.com/help.aspx
https://mva.microsoft.com/learningpaths.aspx
Eval Center
https://www.microsoft.com/en-us/evalcenter/
Hands-on Labs
https://www.microsoft.com/handsonlabs
https://moac.microsoftlabsonline.com/Account/FAQ
http://techgenix.com/microsoft-virtual-labs/
Azure
https://mva.microsoft.com/product-training/microsoft-azure#!lang=1033
https://azure.microsoft.com/en-ca/training/
https://azure.microsoft.com/en-us/training/
https://azure.microsoft.com/en-us/blog/
https://docs.microsoft.com/en-us/azure/
https://docs.microsoft.com/en-us/azure/architecture/guide/
Office 365
https://docs.microsoft.com/en-us/microsoft-365/
https://docs.microsoft.com/en-us/microsoft-365-enterprise/
https://technet.microsoft.com/en-us/office/dn788774.aspx
https://technet.microsoft.com/en-us/library/dn127064(v=office.14).aspx
https://support.office.com/en-us/article/Enterprise-organizations-and-Office-365-6e18d402-f35e-415a-83b1-56620d4074ff
MS Feeds
Wiki: https://social.technet.microsoft.com/wiki/contents/articles/3203.wiki-cloud-portal.aspx
Blog: https://blogs.technet.microsoft.com/
Video: https://channel9.msdn.com/
Free books
This is a MVA link to a number of free Microsoft Press books, but it hasn’t been updated since a year ago, kind of outdated: https://mva.microsoft.com/ebooks.
I would recommend this link from Eric Ligman, updated every summer, huge number of books, there is even a PowerShell script that you can download them all at once: https://blogs.msdn.microsoft.com/mssmallbiz/2017/07/11/largest-free-microsoft-ebook-giveaway-im-giving-away-millions-of-free-microsoft-ebooks-again-including-windows-10-office-365-office-2016-power-bi-azure-windows-8-1-office-2013-sharepo/
This site has quite a few rich format content regarding SharePoint:
https://threewill.com/resources/threewill-blog/