What's the Best Way to Make Sure my Cover Letter is Well-Written and on Target?

Learn about the company and read the job posts to figure out what they want.

Then write your letter accordingly.

Cover letters are frequently used just to file your application in the correct bin and then discarded. The meat should be found in your resume or CV.

Moved to Breaking In forum.

There's some stuff about cover letters emails in FAQ #27. Check the Breaking In FAQs above.