First off, go and get Gmail account. Secondly, make a Google search with the following words: google plus. Once you find Google Plus login using your Gmail account.
Inside Google Plus look for a "little cabin" icon up left. See picture below (in Finnish only, sorry).
Choose Hangouts On Air and Create Hangout On Air.
Name your session and choose Share.
You can invite friends by typing in their email addresses. However, this time the whole world is your friend so there no need to do that and you can pass by this option.
Wait until all gets set!
You can start broadcasting live now!
In case you are absolutely sure, choose OK. You have 8 hours live time to spend!
You can find the address of your Live session by clicking the the Link-symbol in the down-right corner.
When you are done, choose red button to close your live session.
Afterwards, look for your live session on YouTube. It takes a while before your video shows up. How did I find my sessions? I have a YouTube channel. All my clips are stored there.