The Cover letter is usually the first thing the hiring manager sees, and is one of the best tools to make a positive first impression.

The following tips can help you make sure you convey the right messages:

• Tailor the cover letter specifically to the job opening and company. Research the firm and the industry through the Internet, trade publications and the library. Within the letter, demonstrate your knowledge of the field and the position's requirements, and explain why your background meets the organization's needs.
  
   
• Be careful not to rehash your resume in the cover letter. Instead, focus on key aspects of your background that relate directly to the job opportunity.
  
   
• Address the letter to the person hiring for the position. Verify and double-check the spelling of the name and the person's title.
  
   
• Take advantage of your computer's spell check function, then proofread carefully. Ask others to proofread for you as well.

Here are some examples:

Sample1    Sample2    Sample3

Courtesy of  http://www.imanet.org/development_career_tools_resumes.asp