When I first started commuting (about 3.5 miles), I wore my work pants. A couple of unexpected wet mornings with a spray of water and dirt all over my butt changed that quick! Now I ride with fenders and bike clothes.

I change in the handicapped bathroom stall and keep a toiletry bag with deodorant, hair gel and spray and a small hairdryer in my desk. I take a my work clothes in my pannier. On the first ride of the week, I take a second pannier with my food for the week.