Our HOA has a festival in the fall with a local band playing live music, Dickey's BBQ, hot dogs, chips, popcorn, cotton candy, snow cones etc. Each family brings their own cooler with drinks, chairs, blankets, etc.
We have it in the park on a street which has little traffic.
As for kids, face painting, bounce houses, rock wall, sometimes a petting zoo, train rides.
It starts about 3:30 and ends whenever everyone leaves. Great time and social event here.
EDIT: as for manning the activities, YES that is important. When looking for volunteers...check the middle school. My daughter is a candidate for National JR Honor Society and they HAVE to complete 24 hrs of volunteer service. SHe had a meeting yesterday and there were 3 neighborhoods listed who were looking for help. THe students who help....get credit for the hours. Works great for everyone!!
Have fun!