We use Hangouts a lot for pairing, standups and interviewing candidates. Google Calendar has a one click feature to add a Hangout link to your calendar events.
This rocks because it's sent in the invite and on your Calendar entry, giving everyone a simple way to access the Hangout event.
Let's make it rock harder
Turn on this and a hangout link is added to every calendar invite.
So auto, much magic, wow.
To display all the hangout events on your calendar nicely, see this.