The typical asking rate per listing is in the $20's per square foot per year. The Sebastopol region is experiencing a a boost in rates. In the last 3 months, the median rate rose $0 per sqft per year. That's a 1% increase in rent.
Compared to the rest of the Bay Area market, the Sebastopol region has smaller rates, so you should have no trouble finding a great deal in this discounted submarket.
In the last 90 days, 4 listings have been listed, which means listings 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 posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 270 sqft. Most buildings in this area are around 2 floors. Most buildings in this market were built in 1991 and are Class B.