A General Philosophy of Quoting
Quote sparingly.
Hand off the mic to other people only when you are doing it for an important purpose that cannot be served as well or better by summary or paraphrase (with attribution, of course).
Writers sometimes “quote dump,” which can cause their papers to feel like a pastiche of the products of other people’s minds rather than the product of the writer’s mind. Readers expect writers to have selected, condensed, synthesized, and filtered the products of others’ minds that they incorporate into their own texts.
Give up the mic only when giving it up is the BEST thing to do and you can articulate a clear rationale for why you are doing it. Be able to answer why you are quoting instead of summarizing or paraphrasing (with attribution, of course).
That said, though, you should sometimes use another text’s exact words. Follow this advice from the Writing Center at UNC for deciding how to integrate and shape quoted material. Follow this advice from Hamilton College on how to punctuate quoted material.