A cover letter is written to introduce a candidate for a job to a potential employer. The cover letter provides an opportunity to make a great first impression and generate enough interest that the reader will want to review your resumé. In other words, the idea is to get the reader past your cover letter and into your resumé. By writing an effective cover letter, you will make sure that your initial impression is not your last impression on an employer -- in other words, to make sure your resumé doesn't get shuffled to the bottom of the pile. Your cover letter should reflect that you are a strong, confident candidate, yet it should not appear boastful or condescending.
What should your cover letter say? It should say enough about you to persuade a potential employer to take a look at your resumé and ultimately call you for an interview. The first paragraph of your cover letter should indicate your interest in the position and why you feel that you are the perfect candidate. The tone of the letter should show that you are familiar with the company to which you are applying. In subsequent paragraphs, include at least one of your strengths or accomplishments that would make you an asset to the organization. Mention that you have included a resumé for the employer's review. In the last paragraph, close the letter by thanking the employer for considering your application. Request an opportunity to discuss your qualifications with the employer further and include a contact number and/or an e-mail address.
Your cover letter should reflect that you are a professional who will represent the organization well. Proofread the document to make sure there are no grammatical errors or typos. If you are not familiar with how to format a cover letter, do an online search for cover letter formats or cover letter examples. Follow customary guidelines for layout and spacing. Unless you are applying for a position with a creative flair, keep the paper for your cover letter conservative. The best choices for paper are white or off-white.