Only provide the reference sheet to employers who ask for it. You should always ask permission of persons serving as your references before providing their name and contact information to an employer. References are an important part of your credentials and you should choose your references with care. Have at least three people who can speak on your behalf. Faculty with whom you have studied and supervisors from present and previous employment are the best references to use if you are seeking employment.
Faculty are the best references for graduate schools.
Do not use any personal references, i.e., friends. If prospective employers request personal references, be prepared to provide them for that particular employer. If a letter is required, ask only those individuals who know you well enough to write a meaningful reference. Hand them a copy or draft of your resume, this is not only a courtesy but also helps them direct their reference to your own plans. It is always helpful to hand your reference a description of the job or graduate program.