It is important to bring other authors' ideas and words into your paper in as seamless and logical a way as possible: making it clear why/how the source is relevant to your argument. The most common way to incorporate quotes/paraphrases is to use a signal phrase that signals or shows that you are bringing in an outside source.  Often a signal phrase names the author of the quoted material, thus introducing the material and making attribution at the same time. Other times the attribution is included in the citation (either parenthetical or in a footnote).  Here are two examples:

With the author named:

In addition, the work of neurologist Oliver Sacks (1985, 1995) provides engagingly written case studies of savants and other individuals with specific brain damage that has affected their intelligences in intriguing ways.

With the authors in a parenthetical citation:

Research has shown that people will sometimes use this "basking in reflected glory" effect for purposes of eliciting certain reactions from others (Cialdini & Richardson, 1980).

Some possible words to use to signal or mark a quote or paraphrase of an outside source:

Additionally, this page at Clark College has a lot of great suggestions and examples about how to use signal phrases effectively.

What is Quoting?
Quoting is “to repeat (something written or said by another person) exactly” and is usually shown with quotation marks as it is here.¹

What is Paraphrasing?
Paraphrasing is “a restatement of a text, passage, or work giving the meaning in another form,” in other words, to put someone else's ideas into your own words.²

What is Attribution? 
Attribution is “the act of establishing a particular person as the creator of a work,” which is done here with quotes and footnotes.³

What is Plagiarism?
Plagiarism is “the use of another’s work, words, or ideas without attribution. It is considered a form of theft, a breach of honesty in the academic community.”⁴

1 Quote. (n.d.). Merriam-Webster. Retrieved November 13, 2013, from http://www.merriam-webster.com/dictionary/quote
2 Paraphrase. (n.d.). Merriam-Webster. Retrieved November 13, 2013, from http://www.merriam-webster.com/dictionary/paraphrase
3 Attribution. (n.d.). The Free Dictionary. Retrieved November 13, 2013, from http://www.thefreedictionary.com/attribution 
4 What Is Plagiarism? (n.d.). Yale College Writing Center. Retrieved November 13, 2013, from http://writing.yalecollege.yale.edu/what-plagiarism
 

From the Brooklyn College Learning Center.