If you haven't heard, Google has made a new extension available called Training for Google Apps. If you're new to Google Apps or just want to know more about them, you MUST install this extension.
One of the many cool things about the extension is that it's app specific. By app specific, I mean that if you're in Google Slides, clicking on the training icon in the upper right will present you with a plethora of training videos about Google Slides. For example, if you're putting together a Slides presentation and want to insert a video but aren't sure how to, simply click on the Training for Google icon and scroll to the video.
And, as the name implies, training is not only available for Google Slides, Docs, and Sheets, but it's also available for other Google Apps such as Google+ and Google Calendar.
I can really see the value for not only teachers but students as well. Now, there's little excuse for a student not knowing how to insert a chart or copy a slide in Google Slides or how to rename or copy a Google Doc.
I couldn't recommend installing this extension enough. If you use Google Apps, installing is a no brainer.