Most listings are in the $20's per square foot per year. The Garden Grove region is going through a a rise in rates. In the last 3 months, the median rate rose $6 per sqft per year. That's a 30% rise in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Garden Grove region has lower rates, so you should have no trouble finding a great deal in this discounted region.
In the last 90 days, 20 listings have come on the market, which means new availabilities 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 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 1,590 sqft. Most buildings in this region are close to 2 floors. Most buildings in this market were built in 1982 and are Class B.