You absolutely should have a cover letter if there is any place for it. Even if it says a cover letter is optional, write one. Sometimes there is no place for a cover letter in the online application, but there is a place for additional documents. In that case include your cover letter as one of those additional documents. If there is no place for a cover letter or additional documents, I do not include one. I know someone who would put it in the same file as their resume as the first page. That didn’t feel right to me, and when I was a hiring manager, it would have struck me as over the top. At this time I have not asked current hiring managers their opinion.
I was advised that my initial cover letters were too long. A recruiter said that it should be shorter, and more to the point. In general, I would recommend that you read websites about cover letters. Most of the books I found are just part of books on resumes. A couple of points:
- If you’ve talked to people from the company, bring that up.
- Connect your skills to the job description, and how you can help them solve their problems. If you’ve spoken to someone from the company, you should have a better feel for this.
- Do some research to see if you can figure out who the hiring manager is, or at least, the lead HR person for hiring. Address your cover letter to that person. It shows your due diligence.