On a practical day-to-day basis, what should government do -- specifically?

Like should it do education, or should that be private? Should there be welfare, or if not, what should happen to poor people? Should there be public retirement and health programs? Or should people take care of that on their own? Roads? Environment? Arts? Scientific research? Airports? Safety regulations?

As specifically as you can get it—what tasks do you think government should be doing and which ones should be more in private hands?