(with acknowledgment to Gordon Harvey's Writing with Sources)
1)Quote only what you need or what is really striking. If you quote too much you may convey the impression that you haven't digested the material or are merely padding the length of your paper. When possible, keep your quotations short enough to embed gracefully into one of your own sentences.
2)Construct your own sentence so the quotation fits smoothly into it.
Example A: Such a bird has proved, writes Diamond, "that he must be especially good at escaping predators, finding food and resisting disease."
Example B: Zoologist Amotz Zahavi argues that "self endangering behaviors in animals...may be at once a signal and a proof of superior powers."
3)If you must add or change a word in the quotation to make it fit the grammar of your own sentence put brackets around the altered word.
Example: A source passage like "nostalgia for my salad days" might appear in your sentence as "He speaks of nostalgia for [his] salad days."
4)Avoid using the device described above if you can! That is, always try to construct your sentence so that you can quote verbatim.
5) Usually announce a quotation in the words preceding it. In most cases, your reader should enter the quoted passage knowing who is speaking so he or she won't have to reread the passage in light of that information.
Example A: The protagonist of Raymond Chandler's The Big Sleep, Philip Marlowe, describes himself at the start of the book as follows: "I was neat, clean, shaved and sober, and I didn't care who knew it."
Example B: According to David Fine, "a new vision of evil rushed in upon the American consciousness" in the 1930s.
6) Choose your announcing verb carefully. Don't say "Diamond states," for example, unless you mean to imply a deliberate pronouncement, to be scrutinized like the wording of a statute or a Biblical commandment. Choose rather a more neutral verb ("writes," "says," "observes," "suggests," "remarks," "argues") or a verb that catches exactly the attitude you want to convey ("laments," "protests," "charges," "replies," "admits," "claims," "objects," etc.)
Example: Marlowe taunts General Sternwood's butler, who asks "Are you attempting to tell me my duties, sir?" Marlowe replies with amusement, "No. But I'm having a lot of fun trying to guess what they are."