The most useful questions in journalism

There are many different ways to try and collect information from subjects for an article; some good, and some bad.
A good way to conduct a useful interview is to avoid lengthy questions. The shorter the question-- the easier it is to understand, and the better, clearer answer you will recieve.
Also try to avoid cliches. This includes questions with obvious answers, such as asking a cancer patient, "how do you feel?"
Try a more open approach, by asking questions that you actually want to know the answer to. Start by asking them to recount the story, and make sure you go over it numerous times to make absolute sure that what they are telling you is fact.
Always question their knowledge and sources, and be sure that every question is open; i.e. it requires more than a one word response.
Try to keep them talking by dropping small words and sentences into the conversation, like, "and...?", and "what was that like?"
Another strong focus point is to try not to be intimidating. Appear warm and friendly, and treat them like they're your friend. If a subject is reluctant to talk, persuade them by reasurring them...your task is to gain their trust.
One of the easiest ways to get around this is to chat with them about other things, rather than the topic in question. Discuss the weather, their kids, and other trivial affairs, until they fell as if they know you enough to get into the real details.
And, of course, most importantly, take notes. Whether or not you do this openly, or in a sly fashion, let the subject know thats what you will be doing, and brief them on the interview beforehand.
Preperation is the key.