1. A cover letter is not as important as a resume.
A cover letter is just as important, if not more, than a resume. If an employer LIKES what they see in your cover letter, they will be more likely to LIKE what they see in your resume (this is called the "halo effect" for you psychology buffs). If an employer DOES NOT LIKE what they see in your cover letter, they may never get to your resume!
2. A cover letter is intended to give an employer an overall understanding of your past.
A cover letter should give an employer an understanding of WHAT YOU CAN DO now and in the future. It should not be an extensive description of your past.
3. Your cover letter is simply a repeat of your resume.
A cover letter should "personalize" your information and identify how your skills and experiences are directly relevant to the position you are applying for.
4. You should try to dazzle an employer with a cover letter that is filled with large, fancy words.
Keep your cover letter clear and to-the-point. If you can replace a large word for a clearer, more concise word, DO IT (i. e., repair—fix, assistance—help)!
5. Cover letters should be written in paragraph style with no variation.
Just as in vocal communication, you can emphasize your most important points in a cover letter.
To do this:
Use bullets to emphasize relevant qualifications
Use underlining or bold to emphasize a word or phrase.
6. It does not matter what kind of font/printer/paper I use to create a cover letter.
These components of a cover letter a very important, especially if you will be sending your resume and cover letter through the mail. Ensure that your cover letter is visually appealing by printing it on a laser printer on high quality resume paper (your resume and cover letter should be printed on the same paper).
7. A cover letter should begin with the salutation, "To Whom it May Concern".
Try your best to find the name of the person who will be receiving the letter. If this is not possible, use a position title in the salutation (i. e., Dear Hiring Manager:)