Citing the work that supports your research is both an ethical issue and a legal issue.
The ethics of citing is based on the scholarly tradition of giving credit for information and ideas that are not one's own. Science has a long tradition of acknowledging priority through citations. You have the ethical responsibility to cite all works that were used to support your research, to give credit to the earlier work and to provide a clear path for those who follow in your footsteps.
As so eloquently expressed by Isaac Newton in a letter to Robert Hooke in 1675 (Merton 1965),
If I have seen further it is by standing on ye sholders of Giants.
The legal issues of citing one's sources are codified in Copyrights, Title 17 of the U.S. Code, which describes the legal protections of authors' and creators' intellectual property rights.
Merton, R. K. (2006). On the shoulders of giants: a Shandean postscript. New York: The Free Press. p. 31.
The University of Hawai'i Systemwide's Student Conduct Code defines plagiarism as follows:
...includes, but is not limited to, the use, by paraphrase or direct quotation, of the published or unpublished work of another person without full and clear acknowledgement. It also includes the unacknowledged use of materials prepared by another person or agency engaged in the selling of term papers or other academic materials.
Office of the Vice President for Student Affairs, University of Hawaiʻi. (2014). II. Definitions. In University of Hawaii Systemwide Student Conduct Code (Executive Policy (E7.208). Honolulu, Hawaii: University of Hawaii. Retrieved from http://studentaffairs.manoa.hawaii.edu/policies/conduct_code/definitions.php .
Example citations based on rules from: VandenBos, G. R. (Ed.). (2010). Publication manual of the American Psychological Association (6th ed.). Washington, DC: American Psychological Association. Available at Hamilton Library Reference BF76.7 .P83 2010.
Citing a Journal Article
Blackburn, N., & Fenchel, T. (1999). Influence of bacteria, diffusion and shear on micro-scale nutrient patches, and implications for bacterial chemotaxis. Marine Ecology Progress Series, 189, 1-7.
Zar, J. H. (1999). Biostatistical analysis (4th ed.). Upper Saddle River, N.J.: Prentice Hall.
Citing a Chapter in a Book
Haybron, D. M. (2008). Philosophy and the science of subjective well-being. In M. Eid & R. J. Larsen (Eds.), The science of subjective well-being (pp.17-43). New York, NY: Guilford Press.
Citing a Dissertation
Eve, T. M. (2001). Chemistry and chemical ecology of Indo-Pacific gorgonians (Doctoral dissertation). University of California, San Diego.
Zotero, a FireFox plugin, is a useful tool to help you manage your citations
For more information, see to the Zotero Guide.
Endnote Basic is an application that imports citations from your searches in web databases and helps you organize your references. It works with Microsoft Word helping you create in-text citations, footnotes, and bibliographies. See the EndNote Basic Guide for more information. A paid version of Endnote is available as well. See the EndNote Guide for more information.
Mendeley extracts citation data from downloaded pdfs and other formats thus helping you manage your library of papers. You can export your citations from Mendeley as Endnote XML, then import into Endnote using the XML filter. To transfer the documents you've save in Mendeley, simply transfer the saved files in your Mendeley My Collection folder to the Endnote Data folder (into the pdf folder) --your citations with pdfs will then be imported. Mendeley works with OpenOffice and Word to create citations in your document.
See the Mendeley Guide for more information.
CiteULike is a web-based citation management tool that allows you to share your citations at different levels of privacy. You can associate full-text articles with your citations thus always having your library available to you when you use different computers. Compatible with Zotero and Endnote. CiteULike also works with Word and OpenOffice.