When quoting someone, you must cite the source in the body of the paper.
If you include the person's name in the lead in to your quote, simply put the page number:
As Adam Weissberg wrote, "The most important band in history is The Ramones" (24).
If you don't include the person's name in the lead in, include it in the citation:
The Ramones have been called "the most important band in history" (Weissberg 24).
3. Two authors: (Johnson and Wales 42).
Note that there is no punctuation between the author's name and the page number. The period goes outside the parentheses.