I don't personally want to do this, but I'm curious. Is it a paid position, for which they interview and hire people?
If that's the case, then what are the qualifications? I mean, they can't be that picky, right?
All Yahoo staff are hired through Yahoo, including Yahoo Answers team members. All this is done through Yahoo's career site:
As to what the qualifications are, if and when such a post is listed, it will include the required qualifications.