Perform research to learn all you can about the author. If the interview is about a specific book, then read it carefully, making several notes; otherwise try to read selected works of the author. Understand the author's history, his genre and his success.
Warmly welcome the guest onto the stage. Give a brief and flattering introduction to the writer, including information on recent books and impressive statistics such as his status on bestseller lists and number of copies sold. Introduce yourself as well.
Ask pertinent questions that you have carefully formulated beforehand. Ask about how the author got her start and where she gets his inspiration. Let her share her success and the obstacles she overcame to get where she is now.
Ask about the meaning behind the book you are discussing or the books in general. Inquire about the writing process and how the author formulated the book(s). Talk about characters in the works and how they came to life.
Invite the writer to discuss a special subject or project of his choice. Pose it as an open-ended question or bring up a prediscussed special project. It may be a current book, a career change or a future endeavor.
Keep the conversation flowing smoothly. If the author and audience welcome it, you can inject a small amount of humor in the form of a joke. It is important to engage the audience and help them to relate to the author.
Give the writer a chance to talk without interruption. Do not break in while the author is speaking unless you have a good reason such as if he is clearly at a loss for words, rambling or going past the specified time. Instead gently guide him towards new and interesting subjects.
Keep good eye contact with the author and appear interested. Help clarify points he brings up if they would not be clear to the audience. Encourage him to elaborate on interesting subjects.
Conclude the interview by thanking the author for his time. Give a final plug to the author's current and future work. Bid goodbye to the audience yourself and discuss future interviews as applicable.