I have been using Google Classroom for a number of months now and I like it a lot, the recent release of a dedicated app and updates to classroom itself were much needed. My biggest wish now is that you could collaborate with pupils from other schools, hopefully that will come soon.
For now, there are lots of resources around to help you get started or develop your use of Google Classroom, here are some of the best:
A great infographic to be used as a class resource sheet, Alice Keeler also has lots of other classroom resources:
http://www.alicekeeler.com/teachertech/2014/12/01/google-classroom-student-quick-sheet-guide/
A playlist of videos courtesy of Mark Anderson:
http://ictevangelist.com/resources-to-learn-how-to-use-google-classroom-on-ipad-as-teacher-or-student/
A user guide on how to use the Classroom iPad app:
http://www.educatorstechnology.com/2015/01/excellent-google-classroom-visual.html
