When choosing an effective referee can be critical. If the referee is called unexpectedly and has not been briefed about the job requirements you may not get the reference that you would like or will secure the job for you. References are the final stage in the selection process. You already have the job you just need to keep it.
Be selective when choosing a referee. Try where possible to choose someone from the same city, province, country where possible. Employers are not comfortable about references from far away, there is a belief that they may not be authentic. Choose previous employers where possible.
You should also choose co-workers, previous employers, individuals with standing in the community to give a personal reference.
Some employers like these as they can get more details from personal references. You must contact these people brief them on the type of work you will be doing and the attributes necessary for the employment. Check they are willing to give a reference and confirm you have all the necessary contact details.
Find at least 6, the employer will need not more than 2 but if one of your chosen referees is out of town it could hold up your start date. Type up their name and details, the length of time they have known you and their relationship to you.
Take these printed details with you to your interview and hand it over when the interview concludes.