Recording an interview and playing it back to the whole class may be a good way to get started. Model listening and taking notes. Emphasize the importance of questions. Practice making up questions before interviews take place. Assign interviews in partners.
Students can take turns asking questions and taking notes.
Pre-interview conferences are probably a good idea. Talk over the interview with the students and listen to their questions. As students become more proficient, groups may take over this pre-interview conference task from the teacher. Post-interview conferences may take place with the teacher, a small group, or the whole class. The idea is for the interviewers to talk over their results and get an idea of the direction their story will take.