Be selective about who you choose as your referees - consider who can give the best overview of your skills, knowledge and experience relevant to the target role?
It varies, but you may need up to 3 referees and these may be drawn from academic referees, work referees (manager or supervisor from your casual, placement, or voluntary work), or perhaps someone who has seen you in positions of responsibility in sporting, student clubs and other community activities and can comment on your transferable skills. These are people to whom you have reported in some objective capacity.
Sometimes the employer may specify what type of referees they want so check your instructions carefully.
When including Referee details in your application always state your relationship to the referee and it is essential that you have asked for their permission first.