I have found J Seymor's a general intro, but yes he makes it all sound to easy and achievable, however I have found that daylength must have shrunk since his time...
Depends on what you want to do, and it is worth just checking out your local library first...
On poultry - anything by Kathy Thear is good and precise, on sheep Tim Tyne's book is excellent, on pigs I have used Carol Harris's book on traditional pigkeeping, on gardening you will find all sorts in the library and most will have some nuggets of info that is useful.... I have used (and own) MOnty Don's Complete Gardener, and recently bought Michael Littlewood's Organic Gardener's Handbook - v useful (bought via abebooks.co.uk), plus the Hessayon guides are good for diseases, if not for how to treat them.... On goats I have too many books already...., but "The new goat Handbook" by Ullrich Jaunas (via abebooks) is good.
and for general intro HFW River cottage cookbook is quite good, I go back and read the pig section every year just prior to slaughter day,
hope this helps, Anke.