To start a Google Hangout On Air meeting, you must:
1. Create a Google+ account and verify your YouTube account. This links your accounts so you can broadcast to YouTube.
2. Add your classmates to your Google+ circles so you can invite them to the Hangout. Circling is like adding friends on Facebook.
3. Start the Hangout On Air, fill out the form, make it private, and invite your circled classmates. Click start broadcast to begin recording your meeting on YouTube for others to view.