How to write a cover letter with letterhead

Your letterhead should begin with your full name, follow by address, telephone number, and email address. Your name should be in bold 14- or 16-point font. While your address and other (up-to-date)  information should be in normal 12-point font. It should be professional and easy to read. You may want to include an extra line under the letterhead to create visual appeal and to separate the letterhead from the rest of the letter.

• Write the recipient’s name, address, and the date below the letterhead. Use 12-point Arial or Times New Roman throughout the entire letter, set your margins to one inch, and use single spacing.
• Address the recipient by his or her proper title (Mrs., Mr., Dr., etc.). If you’re not sure who the recipient is, we advice you to write “Dear Sir or Madam”.
• First paragraph. Tell the employer why you are writing to them in two or three sentences. State the position for which you are applying. It wouldn't necessary to include how you became aware of the position (unless it was through a mutual contact_in which you should make the most of the connection). 
• Outline your qualifications in the middle paragraph(s). Make sure to match them to the requirements of the position. Make your qualifications jump out at the reader by researching the company to which you are applying for a job and tailoring your letter accordingly. This will also be useful if you get an interview. In your research, provide an up-to-date answer to the following questions: What is the employer's mission? What do they promote as the one thing that sets them apart from their competitors? What kind of customer base does the employer have? Who is their target audience? What is the company's history? Who founded it? How has the business evolved? What are the main highlights of the company's performance over the past few years?
• Include a positive statement in the final paragraph that will motivate the employer to contact you. This closing paragraph should be between two to four sentences. Direct the employer to your enclosed resume or CV and make sure you specify that you're available for an interview. Finish off by thanking the recruiter for their time and consideration, and welcome them to get in touch with you to continue the conversation.
• Write an appropriate closing. It’s a good idea to thank the reader for his or her time. After that, write “Sincerely,” “Respectfully,” or “Regards,” (I.e if you address the recipient by name) otherwise, it should be "Yours Faithfully," leave space (for your signature), your name.
• Add your signature. If you will be submitting your cover letter via email, it’s a good idea to scan and add your signature or write it in with a digital writing pad.
• Lastly, make a notation of your enclosure(s). If you enclose something, such as a resume (CV), with a letter, you should indicate by making the notation “Enclosure” or “Enclosures” at the bottom of the letter.