In the ideal world your child's coach will be someone who is a good two-way communicator, both with his or her players and with their parents.
Coach-child communication
He is someone:
your child feels he can talk to;
who is open and friendly (when he talks to her, does he get down on her eye level?);
with whom your child feels he can connect one-on-one;
who doesn't put up barriers to communication, such as clipboards, desks, or assistant coaches;
who polls her players to find out what is important to them, such as how games and practices could be more fun.
Coach-parent communication
You should feel as a parent that you can talk to the coach about your child (playing time, skill development etc.), or his coaching philosophy, and be taken seriously. I don't know how many e-mails I get from parents frustrated that they can't even get the coach to admit the existence of a problem.
A good youth sports coach should:
communicate frequently with athletes and their parents via meetings [1], e-mail, handouts etc.;
invite input from parents about practice schedules and the number of tournaments the team will enter;
hold "drop in" meetings for parents, and ask parents and players to complete post-season evaluations.
look for signs of trouble with athletes or parents and comes up with ways to nip the problem in the bud.
genuinely listen to what players and parents say and try to meet their needs if possible. By listening, a good coach can better relate to his players and understand the true reason for a player's behavior, whether it is slacking off during practice or not performing to her ability in games. That way, the coach can come up a way to motivate the player to perform at his best.
Links:
[1] https://www.momsteam.com/node/1124
[2] https://www.momsteam.com/forums
[3] https://www.momsteam.com/team-parents/coaching/general/ten-signs-of-a-good-youth-sports-coach
[4] https://www.momsteam.com/successful-parenting/parent-coach-relationship/in-season/how-to-talk-to-a-coach