If you've got a little 400 watt turbine with a tail to keep it pointed into the wind you can pretty much stick that up where you want and see if it works. The multimegawatt utility scale turbines need a little more attention to placement.

Air above about ninety feet moves in what are called "parcels", which is quite different from how we experience wind here on the ground. A wind turbine is basically a close air support attack plane mounted on a gimbal; they're very tough but they'll last a whole lot longer with a steady diet of smooth, fast moving parcels. Putting one up in a turbulent spot is like turning a sixteen year old loose with a new 4x4; pretty soon you'll be replacing the gearbox, blade tips will break, and a wind turbine standing idle in a nice, stiff breeze is just a great big money shredder.

Without getting too deep into the contents of the wind turbine placement class, what you're looking for is a north/south spine of one of those gently rolling Iowa ridges without too many trees or buildings to the north and west of the location. Find this and you've got a candidate location. No one puts in a utility scale turbine without at least fifteen months of micrometeorology data from the area. That data has to be collected on site once an initial survey is done - 200' towers with several wind speed and direction gauges are used to do this.