The cover letter is vital to your CV. This is why it is the first page and not an addition. "Please find enclosed my CV" won't get you very far.
Your cover letter demonstrates your writing style better than your CV.
The cover letter puts flesh on the bare bones of the CV. It points out to the employer the information showing that you have the qualities the job calls for, and makes a statement about yourself and your suitability for the job. It should give the personal touch that your CV will intrinsically lack.
What do employers look for in an application?
A survey of employers found the following (from the 2010 Orange County Resume Survey by Eric Hilden)
- 33% Tailored skills from the job description
- 26% Clarity (well-written, formatted, specifying job applied to)
- 20% Details from your CV (additional accomplishments, explanation of any gaps, etc.)
- 19% Your value, not the basics, why we should hire you
- 18% Spelling & grammar
- 17% Personal vision & uniqueness
- 2% Brevity
- 10% I never read them!