Thank you. I am familiar with the concepts of permaculture, but I'm no expert by any means. (Google Geoff Lawton or Bill Mollison if you are interested in learning more about it.) Its basically just trying to mimic nature in the way we grow plants and raise in animals. This is as opposed to mono-culture, such as corn fields, where you just plant one thing in vast spaces. Permaculture will include trees and bushes and perennial plants and animals into a system together where they can all thrive. Your example of how chickens can be used for more than just eggs and meat is an example of permaculture.
You are right that chickens can be a good investment even if the money aspect doesn't show that sometimes. If you use them for it, they can help prepare gardens and thin out brush and all kinds of neat stuff. I hope you step-brother finds success and can share some of that with you. You really can't beat fresh food, plant or animal, its so much better than what we are used to from the stores.
I'm actually reading David Holgren's book about permaculture, so I have an idea about the philosophy of it. But, I dony have much experience on the ground. His book, it's abstract conceptual stuff. I'll certainly read the authors you suggest me, maybe it will make things clearer. Keep up the good work by the way!
David Holmgren and Bill Mollison worked together on the first ever book about permaculture - "Permaculture One". They are pretty much the founders of permaculture, so it sounds like you are starting in the right place. I haven't read any of Holmgren's later books.
I sometimes learn more or learn better from videos and from seeing things than I do from reading books. For me it was easier to learn what a swale was by seeing pictures or video of one instead of reading about it, for example. YouTube has tons of videos from Bill Mollison that I've seen, including an entire lecture series he did that was many hours long. Geoff Lawton also worked with Mollison and Holmgren, and he's got some really good videos out there as well. best of luck finding the information you're seeking.