Citing the sources you use is important, because if you draw upon other people's work in your writing and research and do not acknowledge those sources, you can be accused of plagiarism.
Citations also allow your readers to follow up sources you have referred to enabling the sharing of ideas.
re-cite - is an online referencing guide produced by the University of Melbourne Library. This guide provides examples for creating in-text citations and refereences covering a number of different referencing styles.
For a guide to the available software, have a look at Managing References