The main responsibility of a research higher degree supervisor is to be an accessible advisor. You are required to be familiar with, and to abide by, the University's policies and rules relating to supervision and higher degrees by research.
Taylor and Beasley (2005) in their Handbook for Doctoral Supervisors describe an effective supervisor as someone who enables their candidate to: initiate and plan their research project; acquire the research skills to undertake their project with adequate access to resources; complete their project on time; produce a high-quality thesis; be successful in examination, disseminate their results; and lay the basis for their future career.