Gmail in the classroom

My school system has used Gmail for several years, but I have never used it except to email other teachers and parents. I would now like to set up contact groups so I can send emails to grade level teachers or parent groups without having to put in each email address every time I send them an email. Another thing in email I would like to try and use is Chat. I think it would be a great way to communicate with others that teach the same thing in my school system as I do, but aren't in my building. It would be so easy to share ideas/questions/answers with other teachers not in my building. Another thing I am going to do this year with email is set up a parent group and send out weekly assignments my students need to complete and a list of spelling words the students are working on for the week.