According to Plagiarism.org, the most common reason for Internet plagiarism is improper citing of sources. Mention the author and the work involved directly in the fact you are referencing if it is a major component of the idea. Cite the author and title of the work the first time you use it as a reference in your work. Address who the author is, whether he is a well-known figure or one that is known only in his field or education.
Use quotations when you are using the exact words of someone's work and research. Don't only write the quote because it fills your paper with other ideas, which you should be analyzing. For every quote you use, write at least three to four sentences analyzing it and making it relevant to the subject of your paper. When using a quote that is in context of another sentence, but isn't relevant to your subject, use brackets to indicate words that you add into the quote.You must also list the reference in your bibliography.
When you aren't directly quoting a source but using ideas from it in formulating your paper, you must also cite the source in the bibliography. The bibliography requires the author's name, titles of the works, companies that published the source, dates published and the page numbers of the source.
When in doubt about your sources, ask your professor or consult the guidelines for your organization about how to properly cite your sources. Learn the format, and keep a copy of your guidelines next to you while researching and writing. Two common forms of citation are the MLA Handbook for Writers of Research Papers and the Publication Manual of the American Psychological Association.