Advice to undergraduates:

There are two issues to consider in referencing: the main text and the reference list. The University web pages offer good guidance, but I have no short-cuts to offer - it is a matter of checking each of your references.  Do them as you go along to avoid the stress of leaving it all to the last few days before handing in.

In the main text, give the name(s) of authors and the year of publication.  There are good examples of citing references in the text available at http://libweb.anglia.ac.uk/referencing/harvard.htm

Avoid direct quotations (using the same or very similar words), as they have little value.  A direct quotation tells me (as a marker) that you have read those words.  What I need to see is that you have understood the words.  When you read a book or an article, make notes - try a list, mind map or spider diagram.  The notes are a reminder of the author's ideas, but the list/map/diagram is your own interpretation, where you can also link ideas from more than one source.  If you have understood the points made in the literature, you will be able to turn those notes into an essay that avoids the perils of plagiarism.