Always cite! Whether you are quoting directly from an author's work, or paraphrasing (putting it in your own words) you need to cite. Citing is giving credit for someone's ideas.
Paraphrasing is putting someone else's ideas in your own words and is a great way to incorporate your sources into your paper. However, it doesn't mean changing a few words here and there. You need to really think about what the author is saying and restate it completely in your own words. Remember, you still have to cite, even when paraphrasing. You're citing someone's ideas, not necessarily their words. Take a look at the video to the right and the websites below for more information on how to paraphrase effectively.