Most listings are in the $20's per square foot per year. The Glendale region is seeing a decrease in rates. In the last 3 months, the median rate fell $4 per sqft per year. That's a 14% decline in rent.
Compared to the rest of the Phoenix Metropolitan Area market, the Glendale submarket has smaller rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 36 listings have come on the market, which means new availabilities most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. About 3% of the available leases in the Glendale are subleases, so you will probably need to sign a longer term lease with the landlord directly. 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 1,690 sqft. Most buildings in this region are close to 2 stories. Most buildings in this market were built in 2000 and are Class B.