Google Classroom specific resources
Google Classroom 101 – Most Recent YT video overview
First Day of Classroom – a training site with short videos mostly created by teachers
The Google Classroom Help Center, starting with About Classroom
The Google for Education Help Forum, where users can post questions and product experts answer
For Parents
Guardian’s Guide for Google Classroom
Classroom Guardian Video – Tech Toolkit
For Students
Google Junior Trainer Series – includes short “how to” videos for students