You might want to ask someone in your field for advice, because what we all might think you 'should do,' will differ. For instance, I've told you to keep it concise, because that's what I look for, but in your case it might be better to have some length. (I will rarely read past the first page of a cover letter, mostly because it's really unnecessary in my field.) So, ask before you do something that may not be the right course of action in your case. But one thing to keep in mind ... proofread!!! And then proof it again ... and have someone else proof it again, even down to the most seemingly insignicant details of your name and address, or the spelling of the addressee's name and address. (Yes, typos happen, but catch them if you can.) And spend time thinking about exactly what you want to express to set yourself apart and then do it in the most concise, yet ... enthusiastic (for lack of a better word) ... manner you can. Sometimes it's not just experience I'm looking for, but a 'good fit' for the organization. Write and rewrite. The cover letters I read are fairly basic ... but the details to grammar, spelling and composition are sometimes more important than the actual content. And you can use spell check ... but spell check doesn't help with the 'there, their, they're' mistakes/misuse. But try to use very specific experiences and knowledge you have that hones in on exactly what is being asked for. Yes, this will be on your resume, but find a way to directly match what it is you have to offer to what they need without listing your resume. In my experience of reading cover letters and resumes, there have times when a borderline resume has become an interview because of the cover letter ... and there have been times where that boderline resume has been a 'no' because of the cover letter. Too long and too many errors are usually the reasons. While I may not ever hire someone based solely on a cover letter, that letter could get your foot in the door and could make you memorable (hopefully in a very good way) to whomever is interviewing you. It may also spark an interview question or two.