Unless otherwise specified by the employer, it is a good idea to provide an employer with a range of references so that they can get a feel for who you are. Some people you might use include superiors, subordinates, professors, peers, and major clients or customers. Select people to validate and reinforce what you have stated in your resume. For instance, if your resume states that you "expanded the product line leading to a 23% sales increase," your supervisor should be provided as a reference to confirm this.
Most employers require at least 3 references. If possible it would be good to provide 4 or 5 (eg. 2 previous supervisors, 1 subordinate, 1 peer/volunteer coordinator, and 1 client).
The most important references are generally your superiors. If possible, include at least two previous employers as references. In contacting previous supervisors, potential employers are looking for information about the contribution you made to that firm. Subordinates and peers should emphasize your ability to be a team player. Clients should highlight your customer service skills and interpersonal communication skills.
If you have not had work experience, then you can use professors as references.
Include all the information that a potential employer may wish to know. You should provide the following information: full name, title, organization name, address & phone number (make sure this information is correct), best time to call, and relationship to you. Provide a reference’s work address and phone number unless the reference wishes to be contacted at home.
Your references should not be part of your resume. If employers specifically request that references be provided as part of your application then you should attach them as a separate sheet behind your resume.
Talk to your references before you forward their names to a prospective employer. If they are aware that they will be receiving a call from an employer they will be more prepared to give an appropriate appraisal of you. Give each reference a copy of your job application, job description, and a list of the specific features in your background that you would like for him/her to mention to the employer.
Some employers will actually skip formal reference checking when they have a letter of recommendation from your listed reference. If you are asked to provide reference letters, and if the references do not oppose, write the letters yourself. This way you have control over what is said. Send the letter to the reference for approval and signing. Ensure reference letters are current and written on the organization’s letterhead. When you are obtaining someone's consent to be used as a reference, ask for a letter of recommendation. This way you will have a good idea of what they will say and the letters can be presented to the interviewer in addition to your list.
Check out your references before you list them for a potential employer. Having a friend call them will help you to choose the best references.
During your career search, take the time to send a letter of thanks to your references, along with an update of how your search is going.