Who Needs a Cover Letter?
Everyone who sends out a resume does! Even if the cover letter never "came up" in conversation or wasn't mentioned in an advertisement, it's expected that you will write one. It adds to the wear and tear of looking for a job! But the good news is: the cover letter gives you another chance to emphasize what you have to contribute to the company or organization

It's important to remember that a cover letter should not simply repeat the details contained in your CV. To be effective, a cover letter should achieve three things:

Introduce yourself and why you are applying for the job.
The first paragraph needs to get the recipient's attention. You should be explicit about why you have sent in your CV, i.e. you are interested in their company and you have both the desire and ability to fill the position being offered. Demonstrate your interest by indicating any connections between the employer and yourself. Mention that you have experience in the same field, that you share a common professional interest, or that you have been following the company or industry in the news. If you have been referred to the company by a mutual friend or associate, mention them as the hirer is likely to feel more obliged to respond to your letter. Be careful about how much you claim to know. If you make inaccurate statements regarding the company or the industry, you'll probably be sprung and cause terminal damage to your credibility.

Sell Yourself
The next part of the letter should briefly outline the particular skills you have that will specifically meet the employer's needs. There is no need to go into great detail, your CV is there for that. Use this section to highlight how you will use your talents and experience to benefit the company. Don't emphasise how you think you'll benefit from getting a job with the company. With a pile of CVs to go through, the person reading your letter, whatever they may claim, is unlikely to place your personal fulfillment at the top of their priority list. Keep your use of the personal pronoun "I" to a minimum. Try to use it in the sense of "Here's how I can contribute to your organisation and its goals."

Make a plan
End the letter by indicating what you would like to happen next. Don't leave the ball in the company's court, take action! Tell them where you can be reached, preferably by both phone and e-mail, but don't wait for a call. Indicate that if you don't hear from them within a few days, you will follow-up with a phone call to make sure your CV and cover letter have reached the intended recipient, and to discuss interview arrangements. When doing this, be assertive but make sure that you come across as polite, not arrogant and pushy.