I live in Florida, so it is almost always hot and humid. My commute is about 17 miles each way. There is no shower at work, so I shower in the morning before leaving home.
The perspiration normally pours off of me while I am riding. For about the last mile I slow my speed down considerably to start my cool-down. When I arrive at work, I let myself cool down some more in the air conditioning, try to dry off, apply deodorant and change clothes. Nobody has ever complained about the way I smell, but maybe they are just trying to be polite.
I commute by bicycle 2 to 3 times a week, so I bring fresh clothes on the days that I drive.