A great intro to the admin console hosted by the Global GEG can be viewed at https://youtu.be/Gj_AoFYoP50
There is a great setting in the @GoogleForEdu Admin Console – give someone in your domain support privileges so they can contact support for your domain to help share the load and have a localised contact for multi school domains https://support.google.com/a/answer/1219251#support
Another Video looking at adding Users and the power of OUs can be seen at https://youtu.be/sZFlBSpC1As this was created in partnership with acer