We build at least 2 coops a month...and now chicken tractors. We get scrap wood from all over and make all sorts of cool creations. Here's the latest:
http://jxn.craigslist.org/grd/2952192739.html
We have a bigger one that's going up in the next couple of days.
Just use your imagination. Chickens don't care. The only things I really suggest are make sure you have vent holes or windows and paint, paint, paint...especially on the outside!!! Look at the ad and you can see what we do.
We either get wood from builders who have leftovers, people giving stuff away on Craigslist or sometimes (but rarely) buy things. I'm a photographer so we often do extra driving around and you would be amazed at the things that people give away. Last summer someone had an above ground pool at the end of their driveway. That has been the roof covering (there are USB boards underneath) for 8 coops so far and we still have some left!
Our coops are pretty popular because we take the time to make sure they are built sturdily unlike the ones in feed stores! I was building a chicken tractor for a week til I had surgery last Monday. It's sitting in the front yard of our house next door and I've had probably more than 5 people stop (we live on a somewhat busy road) and ask how much it was. AND ITS BRIGHT PINK!!
So I'll be making them to sell now while Aric builds the coops after I heal from surgery
If you have any questions feel free to ask. If I don't know I'll ask Aric, he's been a woodworker for 30 years.