Gmail in the Classroom

I would like to use Gmail to create a contact list of parents and students in separate groups. I could email parents as a group when things come up that they need to know about like conferences, test and project dates, or even an overview of what will be going on week to week. These are things that we usually send home as a paper copy, but maybe it would reach a larger audience as an email.
I could use the student group to do the same kinds of things, but also to send links to projects or activities that we may be doing. I would like the students to know how to send emails and create groups so that when they are doing project work they can email the group for ideas and what needs to be done. These projects could be done between two different homerooms if they had a way to contact others in their group easily.