A cover letter is a vital component of your job application correspondence. Each time you send out a resume, you will should include a focused, well-written cover letter. In order for a cover letter to be effective, it should be unique to the position for which you are applying. ERS will develop a skillfully written cover letter for you. A general cover letter will address a career field/industry, and a targeted cover letter will address the needs and requirements of a specific job announcement.