Referencing, the Harvard way

Here are some sites which will be useful. Leeds Metropolitan University has (very usefully) produced an accessible on-line guide to the Harvard Referencing system. Have a look.
If you are using loads of online references, you might find the University of Southern Queensland site a useful addition -- it has lots of examples and covers most of the kinds of online referencing you will find you need to do.
Remember, referencing is important and you need to make sure you've been as accurate as possible, both in the way you reference and what you reference.