I've had backyard chickens for 4 - 5 years now and I think I would like to get a little more serious. For example, selecting a breed to keep to sell fertile eggs, and maybe get more serious with breeding. I am wondering where to start educating myself. I have lots of questions but can't really find what I am looking for. Maybe a book that covers the kind of information I need. I love to read and educate myself before doing anything. All I can find are more generic "keeping chickens" books. Can anyone give me some tips. I am currently building a barn this summer and I'm not even sure how to design breeding pens, etc. Thanks in advance.