To avoid plagiarizing someone else's words or ideas, make sure you:
Paraphrase the original text into your own words. Be sure you are not just rearranging phrases or replacing a couple of words.
Use quotation marks around text that has been taken directly from the original source.
Cite every source of information you use to write your paper unless it is common knowledge or the results of your own research. This includes facts, figures, and statistics as well as opinions and arguments.