This will depend on the type of team and age level of the team you are coaching. Recreational teams will often practice 1-2 times a week and play once a week. So you can expect a commitment of about 3-5 hours total including setup, picking up, etc. Add in an additional hour or so for preparation (practice plans, paperwork, etc). Regardless of the age of your team or level, you should recruit a team manager to handle all the league paperwork, snack and make-up schedules, etc. It can be a huge help.A good recreational team schedule to follow is:
U4 - once or twice a week for 30-45 minutes each session
U6-U8 - once or twice a week for 45-60 minutes each session
U9-U12 - twice a week for 60-90 minutes each session
U13 and up- twice a week for 90 minutes each session