Most listings are in the $20's per square foot per year. The Norco region is seeing a a boost in rates. In the last 3 months, the median rate increased $6 per sqft per year. That's a 30% rise in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Norco submarket has lower rates, so you should have no trouble finding a great deal in this discounted submarket.
In the last 90 days, 5 listings have been listed, which means leases most likley are going fast. You'll want to be prepared to make an offer immediately. 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 1,660 sqft. Most properties in this region are close to 1 floors. Most buildings in this region were built in 2006.