There are three main ways to incorporate outside sources into your writing:
Quotations use another writer's exact wording to make a specific point. Quotes should only be used when the full impact of the original text is necessary.
A successful quotation
Here is a quote from Donald Bogle's book, Prime Time Blues: African Americans on Network Television:
"For later generations, the idea of co-starring an African American actor opposite a white one in a dramatic role might almost seem a cliché. But when Leonard discussed casting Cosby (who had not acted before), the concept was considered so daring that I Spy almost didn't happen." (Bogle 118)
Bogle, Donald. Prime Time Blues: African Americans on Network Television. Farrar, Straus and Giroux, 2001.
While it is good to use quotations when they are appropriate, your assignments should be written in your own words. When you draw on someone else's ideas, you need to find other ways to express them. One good way to do this is to summarize content from another source.
A successful summary
Here is an example of a summary of the Bogle text:
Radical for his time, Sheldon Leonard was the first producer to pair an African American and a white as equals in a television series (Bogle 118).
Paraphrasing sounds simple - just rewrite someone else's ideas. In reality, writing a good paraphrase can be very challenging.
A successful paraphrase