Following a Buzz means you have opted in to receive notifications/alerts about that Buzz, for instance when someone posts a comment, or the Buzz is edited. To follow a Buzz, simply click the ‘Follow’ button in the Buzz header . If you are following a Buzz, the same button switches to ‘Unfollow’ - click it to Unfollow the Buzz and stop receiving notifications for that Buzz.
When you create a new Buzz yourself, you as the owner automatically follow it. When you create a Buzz using the New Conversation template, all participants are automatically set to Follow the Buzz so they will receive your messages - they can still manually opt out on the Buzz itself, or opt out directly from the notification emails.