Books on smallholding seem to split into two categories; firstly the encyclopedia type that aim to cover a little bit of everything in not much depth (ooh, a single page on cheese making - how useful!), and those that cover each aspect in more detail.
I do like the encyclopedia type books for inspiration though, even if they soon run out of detail. Practical Self Sufficiency by Dick & James Strawbridge is quite a good coffee table book, whilst
The Encyclopedia of Country Living is a more wordy affair and covers just about every conceivable topic, at least briefly. It's a bit US-Centric, but I have referred to it a lot over the past few years. Edit:
I just found a copy of it online in PDF form.
Some of the John Seymour books are worth a look too. They are a little dated, let's be honest. However, if you are prepared to ignore the out of date bits, many of the ideas and principles underneath are timeless.
As far as single topic books go, they're probably best searched for once you've decided you want to do something and have exhausted more general information sources. That said, we managed to raise some turkeys for Christmas without needing any special knowledge. BTW, have a not particularly old gardening book that says "The Internet is becoming a very useful resource. For example, using "WebCrawler", I was able to find nearly six hundred pages on gardening!"