Referees are very important. Having good referrals always wins. People focus more on their qualifications, skills and spend little time on getting good referees. It is suggested to take time to choose, your job opportunities may be rejected due to the bad association. Employers would like to get extra information about you from your referees like your skills and your experiences. This should match with the information you have provided in your CV and if that matches then it would be treated as accurate and would boost confidence on you. Employers when they contact the referee, they not only ask and confirm your previous position, how long the duration of the job and reasons for leaving, they also want to enquire about your character. If a referee can able to provide character reference, then it will add on.
Referees can be your former employers, such as your manager, supervisor or even mentor. If you are a student previously then it could be your teacher or tutor. Never choose a friend with in the family or neighbour.
When you choose a referee, it is good to ask that person’s permission to give his references to the third party, and is he willing to talk on your behalf. Sometimes single referee can be used for several years or could be your previous work.