Most private colleges -- and more and more public universities -- require letters of recommendation from one or two classroom teachers of academic subjects and the high school guidance or college counselor. Make sure you provide the teachers and counselor who will write your recommendations with a list of the colleges to which you are applying, deadlines for the recommendations and any required forms. It may also be helpful to provide the teachers who are writing your recommendations with a note telling them why you have chosen them to write for you.
If you have not requested these letters of recommendation, do so immediately by speaking in person with your teachers and counselor. And don’t forget to check the policies and guidelines for recommendations of both your high school and the colleges to which you're applying to be sure all requirements are being met.
You can find more information about recommendation letters, such as waiving privacy rights and supplemental recommendations, in Chapter 12, “Recommendations,” of College Admission: From Application to Acceptance, Step by Step.