A cover letter should always accompany a résumé. The cover letter should be no longer than one page and should be in a traditional business letter format. If possible, it should be addressed to the person in charge of hiring.
Cover letters generally follow this format:
Explain why you are writing, the specific job you are applying for, and how you learned about the opening. If someone you know or someone from the company referred you, mention their name. You can get the reader’s attention by mentioning one of your selling points or making an interesting comment about the company.
Tell the employer why you are qualified for the job and why it interests you. Stress your selling points and accomplishments, but don’t just re-write your résumé; expand upon what you already have in your resume. This is the place to focus on specific skills and experiences that the company would be interested in. If you have done your research about the company, you should be able to do this. Show the employer why you would be a good match for the position. This is also where you can explain in further detail why you’re interested in this particular organization.
Let them know you are interested in the position. Tell them how they can contact you (phone and email address) and thank them for considering your application.