Best used car for bikes and children?

What car would you recommend for a short commute and to carry a toddler and a bike? It would be a second car but will need to be able to drop my three-year-old off at nursery and commute a part of my way...

What car would double as a first car for a teenager and a second family runabout?

Please could you advise on a car that would be cheap to insure for a 19-year-old as a first car and that would also double as a second family runaround. It would be helpful to have a reasonable boot for...