Most listings are in the $20's per square foot per year. The Chino submarket is seeing a decrease in rates. In the last 3 months, the median rate fell $6 per sqft per year. That's a 21% decline in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Chino region has lower rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 4 listings have come on the market, which means new listings are probably leasing quickly. You'll want to be prepared to make an offer immediately. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,000 sqft. Most buildings in this market are approximately 1 floors. Most buildings in this area were built in 2003 and are Class A.