The good news is, from the computer models, it is trending a little more offshore. But do not get complacent. I went through Katrina. The computer models missed where it was coming ashore by 30 miles east-west. That made a huge difference in what happened.
You are not in the worst side of it, which is the northeast quadrant. The northeast is where you get the worst rain and tornadoes. Don't get complacent. The other quadrants can be bad.
The hurricane is spinning counter clockwise. That means the tides and waves will be worst on the northwest quadrant. If you are anywhere near the shore, be very careful of high water.
If you are pretty much away from the danger of high water, the way this one is looking, it probably won't be any worse than a bad thunderstorm as far as local conditions. You can get a lot of rain, so consider flooding. And bad thunderstorms can knock out power and block roads. Since this "thunderstorm" will be pretty widespread, expect some power outages.
I don't mean to make light of this one. These things are dangerous. I just don't see a need to panic for Irene. I think and pray it will wind up being more of a non-event than many people in the media suggest since it is trending more offshore, but don't get complacent.
As long as you are out of the danger area for water, you need to take standard precautions like a strong thunderstorm. Pick up things that can become missiles. Repair any loose roofing or siding. Those winds can be strong. The coop does need to be secured to the foundation and/or anchored against a strong wind. It needs to be anyway but this may give you the motivation to get it done.
Good luck! With all the bad weather events we have had around the country this year, we really don't need another.