Google+ is a great resource for teaching staff as well as students. It has the social aspect of "facebook" with the tie into your Google account. My district has just enabled it on our Apps accounts and I am just getting into using it more. I do have one piece of advice, make sure to turn off access for students under the age of 13. If they stumble on the Google+ sign in page and try to set it up, their account will be disabled as Google is sticking to the 13+ rule for social media. The best part is Google Hangout. Think of this as Skype or Facetime on steroids. You can have multiple participants in a Hangout at the same time. This is greta for flipping classrooms, staff PD, or quick meetings. Even better yet, you can record these Hangouts and post them for later viewing!
Google+ is a great part of your Google account! Log in and start playing around! Check out these Introduction Videos.