In a cover letter, keep your remarks brief. Your opening should explain what you are sending and why. In an optional second paragraph, you might include a summary of the information you are sending. A letter accompanying a proposal, for example, might point out sections in the proposal that might be of particular interest to the reader. The letter could then go on to present a key point or two explaining why the writer’s firm is the best one for the job. The closing paragraph should contain acknowledgements, offer additional assistance, or express the hope that the material will fulfill its purpose
Example: During the recent ARRGH convention in Washington, D.C., one of your sales representatives, Dusty Brown, informed me of a possible opening for a manager in your Data Center. My extensive background in programming and my master’s degree in information systems make me highly qualified for the position. In subsequent paragraphs, expand on the qualifications you mentioned in your opening. Add any appropriate details, highlighting experience listed on your resume that is especially pertinent to the job you are seeking. Close with a request for an interview. Proofread your letter carefully.