Always put a comma or period inside quotation marks, even for single quotes.
EX. The paper said "Do this," but the teacher said, "Do that."
If a question is inside quotation marks, then a question mark goes inside the quotation marks.
EX. He questioned, "Does she know my name?"
If the question is not within the quote, then the question mark goes outside the quotation marks.
EX. Do you believe in "love at first sight"?
If a quote has a quote within it, use single quotation marks.
EX. She exclaimed, "But Betty said, 'I hate you!'"