Most listings are in the $30's per square foot per year. The California region is going through a decline in rates. In the last 3 months, the median rate fell $1 per sqft per year. That's a 3% decrease in rent.
In the last 90 days, 9082 listings have been listed, so you'll want to check back regularly for new listings. About 6% of the listings in the California are subleases, so you will probably have to focus your search on direct office leases. 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 2,070 sqft. Most properties in this region are close to 2 floors. Most buildings in this region were built in 1955 and are Class B.