"Don't make me angry," Harry shouted, "or I'll really lose it!"
"You go look for Hagrid," said Hermoine.
Explanation:
In American English, these are the rules when it comes to the ways quotation marks and other punctuation marks are written:
Commas and periods always go inside the quotation marks <em>("You go look for Hagrid</em><em>,</em><em>" said Hermoine.)</em>
Dashes, colons, and semicolons almost always go outside the quotation marks.
Question marks and exclamation marks sometimes go inside and sometimes stay outside.
When you're splitting a quotation in half, you should add a comma after the speaker to separate the speaker from the second part of the quote <em>("Don't make me angry</em><em>,</em><em>" Harry shouted</em><em>,</em><em> "or I'll really lose it!").</em>