The New York Times covered the events of September 1957 from a variety of angles.
Primary source article include:

• Arkansas Troops Bar Negro Pupils; Governor Defiant

• School is Ringed; Negroes go to school in Little Rock as soldiers guard the area

• Little Rock Nine Awarded Medal

To find additional articles, try an advanced search for the keywords Little Rock Nine and limit the date to 1957.

Choices in Little Rock Study Guide
This 173 page study guide offers context and supporting materials for exploring the Little Rock Nine with your students.  An except that might interest you is Elizabeth Eckford's account of trying to enter the high school on September 4, 1957.  It is supplied here with some questions for a guided reflection.

The Lasting Impact of the Little Rock Nine
Presents a 60th Anniversary look back at the desegregation of Central High School.

Eisenhower Library - Resource List
The Eisenhower Presidential Library presents a resource list of primary sources connected to the integration of Little Rock Central High School.  Materials presented include telegrams, diary entries, phone call and meeting notes from President Eisenhower connected to school desegregation.

National Museum of African American History and Culture - The Little Rock Nine
The Smithsonian presents a brief illustrated timeline of the integration of Central High School that includes photographs and artifacts from the Little Rock Nine students.