Inside your broadcast studio, you will see a blue "Go Live" button on the right hand side:
By pressing the "Go Live" button your stream will start being pushed to the streaming application (and any other secondary streaming locations that you have setup).
Regardless if you use RTMP or Onlive's studio, or a recording that you want live streamed - you will need to press this button before anything is shown.
When your stream has finished it's easy to forget to "Go Offline" but this is actually important because if you don't no recording will be generated. Click "End Stream" and you are done!