Everyone agrees on the importance of citing your references, but unfortunately there isn't a general consensus on the system you should use. Some departments write their own style guides that you will be provided with at the start of your course and expected to follow throughout. Others ask you to learn an established method such as the MLA (Modern Language Association of America), the Harvard, the APA (American Psychological Association), the Chicago or the MHRA (the Modern Humanities Research Association). As is hinted in some of the titles of these organisations, the systems are designed with different disciplines in mind and, as such, prioritise different kinds of information. For example, some highlight the date of original publication of a text while others present only the date of publication of the text that you are using (which may be some centuries after the first printing). Almost more important than knowing which guide to use, however, is the rigid adherence to the one you have chosen. The worst thing you can do is to present an incoherent collage of referencing systems in your essay texts and bibliographies. You can purchase software that formats your references in a particular system and no doubt these will become used more habitually; however, at this stage, it is likely that you will still be responsible for manually formatting your own work at least some of the time.