Most listings are in the $30's per square foot per year. The Corona submarket is seeing a an increase in rates. In the last 3 months, the median rate went up $31 per sqft per year.
Compared to the rest of the Metropolitan Los Angeles market, the Corona region has lower rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 16 listings have been posted online, which means spaces are probably leasing quickly. You'll want to be prepared to tour spaces as quick as possible. About 231% of the available space in the Corona are subleases, so you might be able to snag a great spot on a short term. 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 1,600 sqft. Most buildings in this market are close to 2 floors. Most buildings in this area were built in 2005 and are Class B.