How to avoid plagiarism and cite sources

What exactly is plagiarism? It can be defined as the deliberate copying of another's text and passing it off as one's own, careless or inaccurate citation of the literature used, or failure to cite (even if unintentional) of any resource used. It's unethical, and it's basically theft. We have some tips on how to avoid becoming a plagiarist and perhaps inadvertently getting into trouble.