Lots of students have recently been asking about reference citing. The library has a useful guide: Guide to citing references (Harvard System)
(Links updated to latest referencing guide – 1 Dec 2012)
There are related questions on Manchester Business Answers 24/7 (FAQ):
If you are planning to use EndNote for managing your references, take a look at the earlier Harvard referencing and EndNote blog post.
(The term Harvard system is sometimes used rather than Harvard style. This is because Harvard is an author date referencing approach that allows a good deal of flexibility on the detailed formatting of references. It is not described in the detail of styles such as APA, Chicago, MLA, and Turbian.)