Whether you're an interviewer or an interviewee you can help yourself by learning strategies for both sides. Check out "Interview Strategies" at our business database Prendismo Collection (log into Esearch). (At the Prendismo Collection choose the Explore link from the top row and then choose By Theme from the drop-down list. Choose the term Interviewing in the tag cloud. There are several worthwhile sets, but if you only have time for one watch "Interviewing Strategies.")
Even if you are interviewing to be hired, rather than interviewing people to hire, you can learn from what interviewers go through when thinking about what questions to ask.
There's lots of good advice on how to interview people for employment in these brief articles from Inc. Magazine.
Job-interview.net includes an "Interviewer's Guide" to help you ask the right questions when you are looking to hire. http://www.job-interview.net/