Find a broadcast hosting site online. There are several of these sites such as Ustream, and Justin.tv. Below in the resource section you will find these and other sites to host your broadcasting.
Sign up for an account in order to create a your own specific page. Copy the URL of the page by highlighting and pressing "Cmnd+C."
Paste the URL into an email invitation to your show. If you have a website for your performance group, post the URL and show information there as well. Make sure to include information about what timezone you're in so potential viewers don't miss the show.
Sign into the broadcast site on the day of the show. Command the site to broadcast your show. Usually there is a button that says "broadcast" but the words vary depending on the site.
Pick the Macbook web cam as the device you want to broadcast from when you are prompted. Once you pick this out the stream starts.
Set the Macbook in a location where the web cam frames the performance so the online viewers are able to see the stage clearly. Adjust the cover back and forth as needed to change the angle of the camera.
Turn the microphone level up to the maximum setting. Click on the "System Preferences" icon and then the "Sound" icon. Click and drag the setting bar to the right to maximize the input level.