The wind force is located the place you wrote, I just remembered wrong :D

Amplitude

This is strength of the wind, so if you crank that up it will be like a storm.

Turbulence

This causes chaos to the wind so to speak, so instead of being a steady stream, like you might have in a wind tunnel running at constant speed. Turbulence as I understand it, will cause the wind strength to be uneven the higher the value the more chaotic the wind will be. Exactly how it works im not sure, but I assume that its like a -/+ change to amplitude over a give period of time

Spread angle

Is the area of effect, this is as far as I know actually a cone shape even though it just looks like 2 lines. So every cloth item within the spread angle will be affected. . Range

Is sort of like spread angle except the distance from the wind force to the cloth item. So the range and spread angle need to cover the cloth items for them to be affected.

Im not sure if there is a build in falloff so the wind is strongest at the source and weakest at the maximum range or whether its a constant strength based on amplitude. But guess that is fairly easy to test.that I used in the image, I cant really remember, it was just some random values until i thought it look as i wanted. The settings you have to use is highly depended on the cloth and the air damping setting in the cloth room. The higher the air damping (1.0) the more the cloth will be affected by the wind.