I am a teacher with a short commute (about a mile). As I have twin
toddler boys, staying in shape has become a little more important
lately. So I'm looking for some advice on buying a "commuter" or
urban bike. As there seem to be a lot of "commuter-friendly" bikes
out there, I'm not sure where to look for some good ideas.

Before my kids were born, I used to ride a nice Bianchi trail bike but
that's all I know. Any direction you all might be able to offer would
be appreciated. Thanks!