Connect the negative cable end (black) to the negative battery terminal on the booster car (marked with a "-"). Finally, attach the other end of the negative cable to an unpainted metal surface on the engine of the dead car. Find an unpainted bolt or bracket that is as far from the dead battery as possible. This will provide a solid ground while further reducing the possibility of igniting any hydrogen gas.I was just reading a book in a bookstore and they had this very important step wrong!
I think it was this book, How to Mow the Lawn: The Lost Art of Being a Man.