Keep enough control so that you can hear what everyone says, but don't stifle the group's excitement. Use your instincts to determine how long to let this round continue. If suggestions are starting to slow down or the page is filling up, move on to the next step. Just be careful not to dampen the enthusiasm if things are really clicking. Remember, one goal of this kind of activity is to inspire collaboration, teamwork and camaraderie.
Graphic organizers work with any age group or skills level, from kindergartners to adults.
If kids are too young to read, draw a simple picture instead of writing the word. Better yet, do both, especially if part of your goal is to work on elementary language skills. This question can go in many different directions, depending on your goals. We almost always use three levels in this kind of map, but that's not a magic number. Sometimes you may want to use more or even less, depending on your objectives.