If you're looking for a resource to help you design a garden that will work well with your hens, Free-Range Chicken Gardens may be a good resource. From the book's website:

In Free-Range Chicken Gardens, award-winning garden designer Jessi Bloom covers everything a gardener needs to know, including chicken-keeping basics, simple garden plans to get you started, tips on attractive fencing options, the best plants and plants to avoid, and step-by-step instructions for getting your chicken garden up and running.