Paragraph 1: Use this first paragraph to spell out the position you are applying for and where you saw the job advertised. You should mention that you believe that you have the necessary skill sets to make the position your own, and you can elaborate on these here, very briefly.
Paragraph 2: This section allows you to go into detail about why you think you are suitable for the job. You can mention Qualifications and previous work experience.
Paragraph 3: Conclude your letter by reiterating your strong desire to be considered for the post, and thank the employer for taking the time to consider your application.