1. Using Secondary Sources

2. According to the Norton Introduction to Literature...
"...almost all texts and authors are the subject of actual public conversations, often extending over many years and involving numerous scholarly readers. A research essay can be an opportunity to investigate this conversation and to contribute to it. In this case, your secondary sources will be works in which literary scholars analyze a specific text or an author’s body of work.
Join the Conversation

3. Writing about literature
Biography, history, and literary criticism
"In practice, however, many secondary sources cross these boundaries. Biographies of a particular author often offer literary critical interpretations of that author’s work; works of literary criticism sometimes make use of historical or biographical information; and so on. And you, too, may want or need to draw on more than one kind of source in a single essay."
Writing about literature

4. Secondary sources serve to...
opinion (or debatable claims)—other readers’ views and interpretations of the text, author, or topic, which "you support, criticize, or develop"; 
information—facts (which "you interpret") about the author’s life; the text’s composition, publication, or reception; the era during, or about which, the author wrote; or the literary movement of which the author was a part; 
concept—general terms or theoretical frameworks that you borrow and apply to your author or text.
* Gordon Harvey, Writing with Sources (Indianapolis: Hackett, 1998) 1.
Secondary sources serve to...

5. give the source credit for having this idea or stating this opinion before you did (see Using Sources Responsibly); 
encourage readers to see you as a knowledgeable and trustworthy writer, one who has taken the time to explore, digest, and fairly represent others’ opinions; 
demonstrate that your opinion isn’t merely idiosyncratic because another informed, even "expert," reader agrees with you.
Function 

6. Keep your argument central
 "...your argument should be the focus of your essay, and secondary sources should be just that—secondary. They should merely serve as tools that you use to deepen and enrich your argument about the literary text. They shouldn’t substitute for it. Your essay should never simply repeat or report on what other people have already said."
Keep your argument central

7. Integrating Quotations
Tips:
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Integrating  Quotations