Starting with the overview (hat tip to MSPU for reminding me of this channel), with a different, female narrator:
And then onto the main series, starting with the general introduction:
Next, it's the user interface, including a special mention for Continuum:
The third video in the main series is on features:
Fourth, it's a guide to signing in, needed for all the Cloud syncing:
Fifth, it's accounts, looking at all the various ways of hooking everything up with the Microsoft Cloud:
Sixth up, there's an introduction to the collaboration features available if you have a Office 365 subscription:
Penultimately, and really just for business customers, there's a look at managing Office 365 and troubleshooting license issues:
Finally, there's a look at saving and sharing (e.g. why can't you 'save as'?):
So, as I say, not really a comprhensive Office tutorial, but certainly a useful primer and resource for using the application suite under Windows 10 Mobile...