Research the professor's full name and title by looking at her entry on the Faculty and Staff page of her department's website. Professors have three ranks: Assistant Professor, Associate Professor or Professor. In addition, the professor might have an additional title, such as "Chair of the Literature Department." Use these titles appropriately or you may offend the professor that you are writing to.
Begin the letter by typing your address. Skip a line and type the date, then skip a line and type "(Full name), Ph.D.," the professor's title and any additional titles, the professor's department, the university, and the department address. For example, your header might look like this:
1214 Rock Creek Dr. San Angelo, Texas 76901
April 22, 2011
Dr. Sheila Arlington, Associate Professor Chair of Biochemistry Biology Department Texas A & M University 1234 University Drive College Station, TX 74545
Type "Dear Dr. (Name)" followed by a colon.
Start the first paragraph by introducing yourself and explaining the purpose for the letter. Even if you are in the professor's class, he might not remember you offhand. Identify yourself and explain which course of his you are attending.
Follow up with relevant details. Maintain a respectful tone throughout the letter, and keep the details brief and relevant.
Thank the professor for her time. Provide your telephone number and e-mail address in case she needs to contact you about the letter.
Type "Sincerely," and skip three line spaces. Type your full name. Print the letter and sign your name over the typed name.