Gmail in the classroom

I use Gmail for myself, but could utilize it much more then what I do right now. I star important emails, messaged on chat, and have created folders for messages to go into.
I would like to create a "group" contacts and make a parent group to send mass messages out to. Our school district has all students under a Gmail account, however, 4th grade and up are only able to use it. I teach 4th grade, and our students check their email, but not often. I could see myself as sending out an email for assignments and having students get more practice by entering usernames/passwords as well as typing practice.

I teach online and have to send out group emails often.  I also teach private classes and will use groups to facilitate emails...so as not to miss anyone!