How do I get a copy of the Resource Management Act?

The Resource Management Act (RMA) is available from www.legislation.govt.nz

Specifically the Act can be viewed as a web page (.html) at the following site;
http://www.legislation.govt.nz/act/public/1991/0069/latest/DLM230265.html
Or it can be downloaded as a pdf from the same page.

I recommend that if you need to consult it (and that's a good idea) that you download your own copy for reference.

The RMA is the Act that the Council will need to ensure that it abides by when making a decision on a resource consent.
One of the best ways of making a good point when submitting to the Council on a Consent is to demonstrate that it breaches the RMA. It is a pretty weighty tome, and can be as confusing as a legal document normally is, but if you want to get the attention of a Hearing Committee, let them know that the application violates a portion of the RMA.
Given that this will be a legal matter, it would be beneficial to have a legal opinion on the matter. However, there is a better than average chance that the Committee hearing the application will take you seriously if they realise that you have done your homework, irrespective of whether or not you've consulted a lawyer (make sure your argument is sound!).
In the event that there is some doubt about the application of the RMA to the resource consent application, it also warns all involved that you could be preparing to appeal the decision if you believe that thee is a case to be heard in the Environment Court. This is a good thing as they are far more likely to take your issues seriously if they think that they will get pulled up in Court over it.