The typical asking rate per listing is in the $10's per square foot per year. The Anaheim submarket is going through a an increase in rates. In the last 3 months, the median rate went up $17 per sqft per year.
Compared to the rest of the Metropolitan Los Angeles market, the Anaheim region has lower rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 40 listings have come on the market, which means office spaces are probably going fast. You'll want to be prepared to tour spaces as quick as possible. About 78% of the available space in the Anaheim are subleases, so you might be able to find a shorter term or below market rent. 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 1,710 sqft. Most buildings in this market are approximately 2 floors. Most buildings in this area were built in 1982 and are Class B.