Follow the quotation immediately by the source reference, including page number. If you do a footnote, endnote, or parenthetical citation, it goes at the end of the quote, and is indented with it. Opinions of the authors that you read that you are stating in your paper. Plagiarism is taking the exact words that someone else says and incorporating them into your paper without quotation marks or a source citation. Taking someone's words and altering them somewhat so they are not an exact copy of the other person's language and not including a source citation is also plagiarism.
Plagiarism is extremely serious.
Parenthetical citations must include year of publication and page number. If you do not have much experience writing research papers you will probably need some extra help. The sooner in the semester you seek help from me, the better. With a class this size I do not have time to read drafts of papers before they are submitted. Writing problems are nothing to be ashamed of.