Many scholarship applications, and some college applications, require letters of recommendation. For many scholarships, you will need at least two, if not three letters. Generally speaking, a good rule of thumb is to get a letter from your high school counselor and two letters from teachers who can speak highly of you or one teacher and an employer, coach, or community service supervisor. For certain college applications, you will be required to have a letter of recommendation from an English teacher and a math or science teacher... always pay close attention to the specifics of every college and scholarship application.