What happens if the Queen is pocketed at the break? Is that the end of the game, or otherwise how does play continue?
For full rules look here.
Firstly, the Queen being pocketed doesn't end the game under normal circumstances anyway. It would only end the game if you pocketed the Queen and your last piece at the same time.
You can only pocket (and then cover) the Queen once you have at least one piece pocketed. If you pocket the Queen without this, it's returned to the board and your turn ends.
If you pocket your first piece at the same time as the Queen, you then play to cover the Queen normally.
If you already have pieces pocketed and you pocket a piece at the same time as the Queen, the Queen is covered.
If you pocket your first piece plus one more piece at the same time as the Queen, the Queen is covered.