A couple of excellent websites with tips for avoiding plagiarism.
Think plagiarism is just an issue for college students writing research papers? Hardly! Here are real-world examples of celebrities being accused of plagiarizing.
This practical twelve-page tutorial walks a reader through writing processes that help recognize plagiarism and reduce the chance of accidental plagiarism
(Video by Turnitin.com)
Even if you paraphrase or put something into your own words, you still need to cite the original source.