Hello Puddicat,
I've recommended this book to a number of friends and all of them have found it invaluable. The book is The Encyclopaedia of Organic Gardening it is produced in association with the HDRA (Henry Doubleday Research Organisation). You should be able to pick it up quite reasonably on Amazon.
I can also recommend a book Organic Gardening by Christine and Michael lavelle.
You could also look out for books by the following author Lawrence D. Hills on the web. He was the founder of the above organisation and one of the early pioneers of organic gardening his books are there fore very sort after. I can recommend one of his books the title is Grow Your own Fruit and Vegetables.
As for the amount of space you need this will depend on a number of factors, the amount of veg and fruit your going to consume there is nothing worse that having more produce than you can cope and it going to waste, although you could freeze, dry an preserve what you can't use straight away. You should also consider how much time you can devote to your patch, starting with too big a patch will feel rather daunting when the weeds begin to grow. You could think about starting you patch small and depending on how you�re getting on increase you patch as you go. If you have any more questions feel free to get in touch
Hope this helps.
Happy growing
Head Gardener
P.S. You will also find a number of grow your own magazines in W H Smiths I think some of the titles are Grow Your Own and Kitchen garden. If you go organic then one magazine I get is Organic Gardening have a look at the following link
http://www.organicgardeningmagazine.co.uk/