Using the MLA style, parenthetical notation—also called parenthetical citation or in-text referencing—depends on how one uses the author's name with regard to the quoted material, and how much information is being quoted. Let me explain.
Regardless of whether you use primary or secondary resources, if you are quoting a writer or paraphrasing what he has written, you need to provide parenthetical notation with his last name and the page number from which you took the information. This is very important: whether you directly quote what he says or paraphrase it, you must give the author credit! (Only common knowledge need not be accounted for.) See the following example:
It seemed that Morrie had been busy coming up with his own personal culture, and doing so quite some time before he became ill (Albom 42).
Please note: there is never a comma placed between the author and the page number.
In this example, this paraphrase is from a book, and Mitch Albom, the author, gets the credit for what is said, even though it is in my words (paraphrased) because the information, even the structure of his sentences is his! At the end of the sentence, before the punctuation, type an open parenthesis, the author's last name, a space, the page number, and the closing parenthesis. Then add the period. The parenthetical notation is part of the quote. The period follows the parenthetical notation (except in block quotations—see last example).
If you include the author's name as you quote his writing (or paraphrase), you only need to provide notation of the page number—because to give his or her name again in parentheses would be redundant. Note that the author Edith Hamilton is referred to in the following quotation, so only the page number is needed.
Hamilton describes Pan as a "noisy, merry god..." (40).
If you continue to write referencing the same book, but use a different page, you need not mention the author's name again. You can simply adjust the page number in your parenthetical notation. If you reference a new author, you must start again by following the directions above, and do so each time the author changes.
Finally, if you need to block indent, the parenthetical notation changes again. The block indent is when you include an larger quotation. However, in this case, the punctuation is placed at the end of the quotation. Then the parenthetical notation is added, with no punctuation following it. Imagine you have included a lengthy quote of "more than four lines of prose." The entire quotation is indented into one block that makes it stand out from the rest of your writing; at the end of the last line, you punctuate as follows:
...and he was always credited as being a fine musician. (40)
You will note that the punctuation is placed before the page number.