Quotations, paraphrases and summaries serve many purposes. A good way to start is to read the entire text, noting the key points and main ideas. Then, select portions that you wish to quote. There are several ways to integrate a quotation into your text. Often, a short quotation works well when integrated into a sentence.
Longer quotations can stand alone.
You will find rules concerning how to cite sorces and puntuate cititions at Documentation guide page. Remember that the reason to use a quotation is to add to the meaning you are trying to convey and choose your quotations accordingly.