Your resume is the star document in the initial screening process, as it contains all of the important information about you. Heaven forbid a hiring manager would overlook something in it, or not read it, which is why many job applicants tend to rehash their resumes' contents within cover letters. But that's one of the worst things you can do. No one wants to read the same information twice, plus that's not the purpose of a cover letter. A cover letter is meant to introduce your resume and sell your qualifications. It's the place to flesh out your most impressive skills and demonstrate how they'll benefit the company, which, in turn, will make the hiring manager eager to read your resume. Unfortunately, repeating a resume's contents in the cover letter is one of the most common cover letter errors. Not only is it annoying to hiring managers, but they often presume you're doing this because you have nothing else to say -- that is, you have no additional skills to offer them [source: Walker].