Two of the most important questions to ask when interviewing candidates for a football coaching position are why they want to be a coach and why they want this particular job. The answers to these give insight into the motivation of the applicant and his approach as a coach. Other areas to explore include football strategy, off-field interactions with players and general life experiences gleaned from football.
There are a number of basic football-related topics that should be covered during an interview. Some of these include the football philosophy of the candidates, how they would run a typical practice and how they intend to create a winning tradition.
It's also important to ask questions about how the applicants interact with and help players away from the field, such as how they gain the trust of the players, how they will help the players improve their grades (if the position is for high school or college), how they handle discipline for off-field behavior issues and what role football plays in their lives.
Additionally, ask questions about their general life experiences, such as what separates them from the other candidates competing for the job, what mistakes they've made in their coaching career and what they've been able to learn from those mistakes. These answers, combined with those covering football-related and off-field topics, will help you get a more complete picture of each of the coaching candidates.