Keep It Simple, Student!
Much of what makes a good interview will come naturally and involves skills you already have (whether you know it or not!) Here are a few things to keep in mind during the interview session:
How you listen during an interview directly affects the quality of the experience for both you and your source. Listening attentively and offering your undivided attention is proper etiquette and makes for a more comfortable environment. Use nonverbal (examples: nodding your head, reacting appropriately to humor, & exhibiting good posture) and verbal (short questions, small words of agreement) cues to guide the conversation and show that you are interested and are following the responses closely.
If a response inspires a new question don’t be afraid to ask it-you often find your best and most effective questions this way.
If you did not understand a response politely ask your source to repeat it or explain a particular point. Keep in mind that repeatedly asking for clarification can give the impression (rightly or wrongly) that you are unprepared or inattentive.
As mentioned above, be prepared to let the interview take you through some unexpected territory but do not let conversation linger for too long off-topic. If necessary, use your questions to gently and politely steer the interview back to the original subject.
Even if you are recording the interview take thorough notes. It will provide you with a written framework of the audio (or saved text) from the interview and serve as a backup in case of technological difficulties.