In what way are they helping people? If it's easier for you to explain it in Chinese I can understand that as well.

ORIENTEERING? You need to re-write that initial post!

What kind of help? There is to donate (Collect money to give to a cause, generally to help people) Sometimes events that are to collect money to be donated may be called benefits Community service (Unpaid labor for an area, generally cleaning litter and such) Maybe the old boy scout cliche of walking the old lady across the street? :P Maybe support? Aid? Save? Assist? You may need to be more specific as to what exactly they're helping with.