Adhering to accepted standards for business letters is the only absolute in writing cover letters. An effective cover letter should include:

1. Heading and Greeting - State the date and your name/contact information at the top of the page. Address the letter to a specific name and (or) title whenever possible.
 
2. Opening and Introduction - Explain who you are and state your reason for writing.
 
3. Body - Here you will sell yourself and charm them. Reveal why you are a perfect and unique match for the position. Explain why you have chosen this employer.
 
4. Assertive Closing - Courteously take initiative toward further action and next contact. You may wish to suggest a time and method (phone call, meeting) for follow up.

Don't bore your target audience with the generic form letter they have read a hundred times before. Don't simply restate your resume either. Check out our list of tips for creating a quality cover letter.