Here is a playlist of "How-To" videos to get teachers up and running with Google Classroom in the SPS environment.
(Click the top right corner to see the list of videos).

Here are a selection of videos curated by Google that may help you learn more about Google Classrooms.
(Click the top right corner to see the list of videos).

If learning from text and images is more your thing, here is a link to some written "How-To's":

https://support.google.com/edu/classroom/?hl=en#topic=6020277