Sheboygan rolls up the sidewalks pretty early in the evening Nick... Couple good places to eat:

Il Ritrovo on South 8th Street (excellent pizza, not your everyday stuff, the real thing)
Stefano Trattoria on South 8th ($$$$, very good authentic northern Italian)
Horse & Plow at the American Club in Kohler (bar/restaurant, usually nice atmosphere)
O's on Michigan Avenue (interesting menu...)
Firehouse Pizza in Sheboygan Falls (goood pizza)
52 Stafford in Plymouth (Irish bar/restaurant)
Gosse's at the Northwestern House on Union Avenue (great food, good prices, but close at 7 pm every night, closed Sunday and Monday)

Stuff to do...

John Michael Kohler Art Center www.jmkac.org
Sheboygan Theatre Company's next show opens on the 23rd, runs through the 31st.
If you want to work out, the SportsCore in Kohler is a very nice facility.

Hmmm, like I said, not much goes on around here during the week...or the weekends for that matter. Probably why there are so many bars around here.