On average, listings lease in the $10's per square foot per year. The Kennesaw region is going through a a boost in rates. In the last 3 months, the median rate went up $18 per sqft per year.
Compared to the rest of the Metro Atlanta market, the Kennesaw submarket has less expensive rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 11 listings have been listed, which means spaces most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 780 sqft. Most buildings in this area are close to 2 floors. Most buildings in this area were built in 2006 and are Class B.