On average, listings lease in the $20's per square foot per year. The Signal Hill submarket is going through a decrease in rates. In the last 3 months, the median rate fell $9 per sqft per year. That's a 30% decrease in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Signal Hill region has less expensive rates, so you should have no trouble finding a great deal in this depreciated region.
In the last 90 days, 5 listings have been made available, which means spaces most likley are leasing quickly. 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 1,340 sqft. Most properties in this market are around 2 stories. Most buildings in this area were built in 1982 and are Class B.