I commute to work and it's @ 11 miles round trip. Here's what I do...

1. Shower every morning - I don't sweat much but if you don't have showers at your work it's best to take a shower before you go.
2. My office environment is very casual so I can get away with wearing shorts all day but I always wear an under shirt and it's usually one of those Target Champion C9 wicking t-shirts (especially during the Summer).
3. I wear SPD/mountain bike shoes but I keep a pair of regular shoes in my office. Today I have just been wearing the SPD's around.

I have a separate bike I built for commuting with a rear rack and panniers. It helps a lot for carrying lunch, my tablet, odds & ends for work and light jacket or shirt if needed.

Just for good measure, here's a picture