Ours is run by a few mums at the church, so they organise a roster for clean up/morning tea etc...

Its also a music based one, so we have free interaction with instrument play for the first 10-15 minutes and then we do songs/action songs etc and play wiht certain instruments for 30-40 minutes then mums have morning tea & the kids play & snack All in all it lasts around 1 hour 30 minutes and there's some structure, but its pretty relaxed too.