Identify the job by title and let the recipient know how you heard about it. Summarize your qualifications for the job, specifically your work experience, activities that show your leadership skills, and your educational background. Ask for an interview, stating where you can be reached and when you will be available. If your prospective employer is located in another city and you plan to visit the area, mention the dates for your trip. If you are applying for a specific job, include any information pertinent to the position that is not included in your resume.
In these days of email and instant messaging, letter writing is becoming a lost art, and especially the formal letter. I’m pretty sure that formal letter rules are still taught in schools, but very little of it sticks. If you’re an executive or other high_ranking person within an organization, you can probably rely on your secretary or assistant to handle the niceties of letter writing, but for everyone else, knowing how to write a strong letter ourselves is important.