I ran a kids' soccer club for seven years. 250 - 290 players; 30 - 40 coaches/assistants; usually around 18 teams. I ordered in their team shirts, made up the game schedules, did coaches clinics, sorted out the insurance (thus was the manager for insurance purposes with the ASA of all the teams), some years I even coached, painted the lines and put the photos in the paper.
All you need is a bit of a system really. Soccer managing is easier than spring cleaning, that's for sure.