Word has templates that you can easily follow for these letters, but if you wish to follow examples, here are a few:
(4 blank rows)
Paragraph 1 – Tell them the position you are interested in, where you heard of it, and/or which department in their company you are interested in joining.
Paragraph 2 – Tell them why you are so interested specifically in their company. Based on the job description, explain to them how you can help them succeed. Tell them about any related experience or achievements you have made that would make you the ideal candidate.
Paragraph 3 – Tell them you are attaching your resume, references, transcripts, etc.
Final Paragraph – Tell them you are anxious to hear from them and get an interview. Also, ask if they need anything else and to feel free to contact you if they have any further questions.
(Type your name)
Enclosure: (resume, samples of work, application, etc.)