Okay, thanks all! We were at the property yesterday and got our septic plan so we know exactly where the field is. We have more space than we thought to allow the chickens to free range. I think we will have a fixed coop near the back of the side fence where it is shady and have the run all along the back yard where it is sunny and shady. They will have about 100' to do whatever they want. I forgot to mention, we have active train tracks behind our house, so I'm not sure the chickens wouldn't just cross over them if not confined. There is a lot of vegetation before them and we also plan to put up a fence, but they could still get around either side since it will be free standing. The idea of moving something around isn't very appealing. I plan to have a garden toward the front side of the house that I can let them out on, as well. I guess I'll have to add a little fence around it so they don't roam into the neighbor's yard. My friend has chickens and no fence and they really don't stray to far from the barn, so maybe I'm giving them too much credit ;-)
Sounds like a good plan so far, just be ready to adjust the plan as you go.
Have fun also!
Scott