Google has a great resource, Google Tips, that provides quick, easy tips for using Google Products.
It is setup in a card format, using simple, easy terms (not tech-speak). You can view all the cards or sort by Category, such as Do More, Save Time, Have Fun, or by Product (Android, Chrome, Gmail, Drive) etc.
Click on the card to get more info. Most have some kind of video to show you how to do it, or very simple instructions. Each card also has a little icon on it showing what it applies to: mobile, video, security, etc.
The cards have great info and are easy to understand.
This is a great resource for anyone, especially schools using Google apps.