Paragraph 1: State why you are writing, how you learned of the organization or position, and basic information about yourself. If you are writing at the suggestion of someone who knows the recipient, say so.
Paragraph 2: Demonstrate your knowledge and interest in the organization, and use specific examples to show how your background and skills qualify you for the position.
Paragraph 3: This paragraph is optional and is recommended for elaborating on particularly relevant or impressive details included in your resume.
Paragraph 4: Indicate that your resume and other supporting materials are enclosed. Reiterate your interest in the position and your desire to meet for an interview. State your plans to follow up via e-mail or phone within a certain period of time and invite the employer to contact you to request additional information. Lastly, thank the employer for his/her consideration.