A good coach:
1. Knows the game--proper technique, good plays, good tactics, good play calling etc. Probably needs to also have been a good player and have coached at that level before.
2. Good communicator--what do you need to improve on, what are your strengths, why I am taking you out, why you are running, why I am yelling at you? Uses the right tone of voice at the right moments and for the right kids. Ask him how he will correct his players.
3. Charismatic--inspires the players, makes the players love him/her despite having to punish/correct every once in a while. This can be done by humor, loving/serving the players, exuding excitement or love for the game--every good coach or teacher has their own style, but not every coach is charismatic.
4. Cares about the players on and off the field. They talk to the players individually about things unrelated to the sport. They know and communicate to the parents. They are approachable, honest, respectful, and listen to the parents, but is not controlled by them.
5. Organized. Practices and games are run well. You know what the schedule is in advance. Ask what he thinks a good practice looks like.
6. A good administrator. Can they raise money for the team, can they handle the overwhelming logistics of it all (tournaments, jerseys, grades, liability)?
7. Cares about the entire program, not just varsity. Do they go to 7th and 8th grade games? Do they do camps? Do they watch and are involved in JV and Sophomore and Freshman? Do they hire good assistant coaches? Are they respectful and supportive of the girls program?
8. Has a handle on his authority. If they are too authoritarian for their own good, then the players will literally hate their coach. If they are a wimp, then the players won't play for him. How much does he care about discipline?
9. Good role model. Does he care about school? Does he swear excessively? Does he lose his temper too much?
That's all I can think of for now.
(Kellie was a 4-year varsity basketball player and a 4-year starter on the varsity soccer team at Timpview. She was also a scholarship athlete on the soccer team at the University of Utah. She currently coaches a premier U14 girls soccer team for Celtic Storm in the Premier 1 division.)