It’s no different than the results enjoyed when you include a great cover letter with your resume. A cover letter is an introduction of you to a total stranger. This total stranger may be your next employer. Your letter must be compelling, personable, and brief. It also needs to be specifically related to the position for which you are inquiring. Remember: this is your first opportunity to make a good impression, and it could be your last. If you include your cover letter in response to an ad, job board, or Internet posting, make sure keywords included in the description of the opportunity are included both in your cover letter and your resume.

The content of your cover letter should include the following:

Proper Address

When possible, your letter should be addressed directly to the person making the hiring decision. If you are unable to obtain that person’s name, address it to a high-level executive in your area of interest. If you are answering a blind ad, you should address it to a human resource professional. You should avoid using “To Whom This May Concern.” Make sure that all names and positions are accurate and properly spelled. Place a phone call to the personnel department and verify all names, titles, and departments.

Salutations

Always address the recipient by name: “Dear Mr. Jones,” NOT “Dear Sir/Madam” or “Gentlemen.”

First Paragraph

In this paragraph, say something that will catch the reader’s attention. Next, state the reason for your letter and the specific position you are applying for. Indicate briefly how you heard about the position.

Second Paragraph

Indicate why you are interested in the position, the company, its products or services and what you can do for that employer. If you are a recent graduate, explain how your academic background makes you a qualified candidate for the position. Point out specific achievements or unique qualifications that differentiate you from others applying for the opportunity. Try not to repeat the same information they will read on your resume.

Third Paragraph

Refer the reader to the enclosed resume which summarizes your qualifications, training, experience, and most importantly, your accomplishments!

Final Paragraph

Indicate your desire for an interview and your flexibility on time and place. Repeat your contact information. Finally, close your letter with a statement or question which will encourage a response. One example would be stating that you will call on a certain date to set up your interview. If you take this approach, make sure you follow up on that exact date.

 Closing

Keep it simple and professional and most importantly, don’t forget to personally sign each letter you send! You never want to MASS PRODUCE your cover letter. You want to customize each letter toward the specific hiring authority, company and opportunity.

Go here for more information and samples of cover letters.