On average, listings lease in the $10's per square foot per year. The Orland Park region is going through a an increase in rates. In the last 3 months, the median rate rose $18 per sqft per year.
Compared to the rest of the Chicagoland market, the Orland Park region has lower rates, so you should have no trouble finding a great deal in this discounted submarket.
In the last 90 days, 22 listings have come on the market, which means leases most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 5% of the available leases in the Orland Park are subleases, so you will probably need to consider the implications of signing a direct lease with the building. 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 600 sqft. Most properties in this region are around 2 stories. Most buildings in this market were built in 2000 and are Class B.