I know my son gets sick of me correcting his spelling and grammar! Really sick. But I still only use one exclamation point.
When discussing the exclamation point, The Associated Press Stylebook (my new favorite reference) advises, “Avoid overuse.” Instead of using a dozen exclamation points find some nice juicy words to flower your prose.
Put the mark inside the quotes when the exclamation is part of the quote: “Thanks so much for the picture of the boys. They’re so stinking cute!” Vicki said. “I know!” I replied.
Put the mark outside the quote when it is not part of the quote: I’m sick of mom telling me to “Look it up”!
When the quote is at the beginning of a sentence, you do not use a comma: “Freeze scumbag!” the police officer yelled.