The Small-Scale Poultry Flock by Harvey Ussery is an excellent read, with one caveat. "Small-scale" is intended to mean anywhere from 25 to a few hundred chickens. For me and many other urban chicken keepers, "small scale" means about four chickens. If you have a small farm or larger homestead, you'll find this book to be incredibly useful. If you live in the city and keep a few chickens, you'll find a lot of useful information in this book, but it shouldn't be your initial basic guide to keeping chickens.
What I LOVED about this book is that it goes beyond simply the basics like housing, feed, and chicken behavior. It is about how to use your chickens as an integral part of pest control and soil fertility. Chickens' contribution to a garden, homestead, or farm is far more than just eggs and/or meat. They provide pest control and free high-quality fertilizer as well. As Ussery points out, keeping several species can be to one's advantage, as geese are valuable for weeding and ducks will eat slugs whereas chickens might not.
Perhaps the best piece of advice he includes is the importance of deep litter, not only as a way to turn manure into compost, but also as a source of nutrition for the chickens. Other books go into the idea of using deep litter as a means of generating heat throughout the winter and as a general lazy person's way of rarely having to clean the coop - but Ussery takes it a step further.
After a while, the deep litter will become a food source for the chickens, and it will furnish them with essential nutrients and improve their health. The key is keeping the litter in the coop for more than a year and never entirely cleaning the coop out so that the microbes in the older litter can inoculate new materials added. Ussery recommends dead leaves, wood chips, or a number of other materials, but cautions against using straw for deep litter.
He also explains how to put the chickens to work in the garden, compost pile, or pasture, allowing them to turn your compost, eat pests, and improve your soil with their manure. He tells how he no longer uses a rototiller and instead uses tiller chickens. As he points out, the rototiller doesn't poop!
There are many, many other useful sections of this book, including how to guard against your flock overfertilizing your soil, how to make your own feeds or allow the chickens to forage on their own, and how to deal with broody hens if you want them to actually hatch their eggs.
Where it falls short is for those who are looking for a basic chicken keeping book but don't have much space and can't keep more than a handful of chickens. I've got a broody hen right now, so I flipped right to the broody hens chapter to see what Ussery said. His advice was of little help to me, since he gave the standard advice about putting your hen in a small cage with no bedding until she stops being broody if you don't want her to be broody (great advice, but I lack a small cage and was looking for other ideas). But most of the chapter was about helping your broody hatch her eggs.
As an urban chicken keeper, my hens find themselves in a very unnatural situation. That is, they have no roosters and no fertile eggs. Ussery recommends and assumes that your hens would have access to a rooster - as they would if you follow his plans completely - so breaking a hen of broodiness just won't be such a constant and difficult problem.
A book that was about someone in my shoes should talk about what happens when your hen is broody for so long she puts her life in danger by not eating or has an outbreak of mites from not dust bathing. I agree that Ussery is right, that my hens should have a rooster, but I'm in a city and they can't. That doesn't mean that his book is flawed, but it does mean that it's probably not the best primary resource for someone with less than 10 hens who lives in a city. It also means that I've already recommended this book to the woman who keeps a flock of 200 chickens on a local organic farm :)
Even if you do just have a few chickens, I recommend taking a look at The Small-Scale Poultry Flock because it does provide so much useful advice that you truly can't get anywhere else. It's excellent not only on soil fertility but also on issues like keeping chickens safe from predators and keeping the chicken feed from becoming a buffet for sparrows and mice. For those with only a few chickens, you might skip the chapters on topics geared for larger flocks like the one on electric fencing, but you will probably find useful advice that you haven't seen anywhere else.