I don't know a guide but I can try to explain. This one was a tough one for me too.
First, I'd not use the governor anymore. I don't know what he does and how, but automated stuff is a bad thing most of the time. It works, but it works but it's not recommended.
If you play Demigod you know what commerce is. It's the amount of 'money' that comes from the worked tiles.
That money is divided into science or treasure, but you can also slide some money towards happiness.
In the screen above, he spends

91 to keep the people happy. Note that these people are still working tiles, so they rake in shields and food also and that's a good thing.
It's better than hiring clowns. Clowns cost you one tile not worked. So they cost money, food and shields.
To use clowns for happiness is like putting the science slider on 0%, but hiring professors for science.
Mind you - it's a slider for the whole country. So if everyone is happy but only one city is unhappy, it's wiser to just make that one city happy by hiring clowns and finish a happiness building.
If the entire civ is unhappy - adjust the slider a little until there are more happy than unhappy people in the cities again.