To log into Google Classroom, first make sure all users are logged out of Google (or the student is logged in on their cr6 account). Go to classroom.google.com. The student then logs in with their school email account and password. They should know this information! It is the same login they use for almost everything. The domain is @cr6.org (that is the part they forget!). If they log in with a different account (or you log in with yours) they will not be able to see their assignments or resources.
Once logged in, you will be on the main stream page. This is where all notifications are. They have 3 main choices at the top - stream, classwork and people. Most things they access via classwork. They can also connect to any other Google Apps through this page at the top right (9 squares which we call the waffle or squares).
From this page, you can get to all our assignments, see due dates and access resources. They are so many things you can get to from here. Your student uses this daily and can walk you through it!