Here is a note about bookmarking the Hangout URL from Google
Mark Chang originally shared:
Bookmark your Hangouts video calls
Whether it's the weekly chat from your dorm room with your parents or that group video call with your fantasy football league, Hangouts is a great way to keep in touch with your friends and family. With today's update, it's easier and faster to get into a Hangouts video call with your favorites.
You can already share a link to a live video call from your browser to invite more people to join. Starting today you can bookmark the URL for any video call and come back to it again and again. Save it to your desktop, bookmark it in your browser, email it, attach it to your calendar -- stash it anywhere you like! Then, when you open a saved Hangouts link, you'll be immediately connected to anyone else that opened that same link. Getting the gang back together again has never been easier.