I wanted to pass along a couple of thoughts on cover letters. Maybe the most common error that I see on cover letters is that they simply rehash the details on the resume. If you are simply going to walk me through the resume, then please don’t send a cover letter. It’s not necessary.
Use the cover letter to EXPLAIN how your experience relates to a specific position. ARTICULATE in a brief statement or two how your particular experience can immediately assist an employer. Simply telling me where you worked and what skills you gleaned from the position (repeated for each position) is not helpful.
Also, like resumes, these documents should be sent in PDF format for two reasons. First, sending them in any other format invites formatting errors. Secondly, and maybe more importantly, sending the cover letter in a format other than a PDF allows the recipient to see how you’ve modified the document (and with a simple control-Z command they can see where else you have applied).
Another thing to keep in mind is that in today’s digital age, it shouldn’t be hard to figure out who is seeing a cover letter. At our company, there are only two people and they are both guys, so I often wonder how much homework someone has done when they address a cover letter to “Sir/Madame”. Although opinions differ on this, I believe that if you don’t know who you are sending your cover letter and resume to then you should not address it to anyone, but instead jump right into the body of the letter without the formality of “Dear Hiring Partner” or “Dear Sir/Madame.”
Finally, please keep the cover letter short. You need to sell yourself, but if the letter is text-dense and long, it’s a daunting task to read the entire letter (when there are 19 other letters/resumes on my desk). Please be concise and summarize why you are a good fit for the position in a couple of paragraphs.