How to mate with queen + king vs bishop and king?

I'm totally new to chess, and I just ended up in this position - how should I have won? I got bored before I figured it out, but I assume it's possible?
Get a book on endings, grasshopper! Your game will immensely improve on all phases of the game, trust me.

I'm totally new to chess, and I just ended up in this position - how should I have won? I got bored before I figured it out, but I assume it's possible?
Get a book on endings, grasshopper! Your game will immensely improve on all phases of the game, trust me.
Better late than never, right? An advice is an advice, even if it's 17 years too late.
Box in the defending king and keep your king and queen on the squares opposite the color of the bishop. It is an easy win. The bishop will be totally overwhelmed by the queen. Here is a demonstration of how it is done:
Why not 12.Q-f8-g7# or 13.Qh4#? Pretty slow altogether.