Must admit that when I first heard about it, I thought there were so many other books around that it would be difficult to add anything new. But John's book is just so good in many respects:
It manages to assume complete ignorance on the part of the reader, which makes it probably the best book around for beginners. Especially valuable as people don't get the chance to learn from parents/grandparents as much as they once did.
There is so much information in there, it is also invaluable for seasoned vegetable growers.
Vegetable growing doesn't stand still. Techniques change, conditions change (eg the climate). This book is 100% up to date. Passing a local allotment a few weeks ago I noticed the amount of black plastic being used to suppress weeds, and plastic compost bins. None of these would have been in evidence 30 years ago.
The book is small enough to slip in your pocket to take to the plot. So you can actually refer to it on site, which makes it pretty indispensible. You can't do this with all the hardback glossy books. And why pay for a book with page colour photographs of vegetables, when this space can be used more effectively for information.
The book also covers the reasons why growing your own is important, as well as how to do it most effectively.
It's not just for allotment people - it's valuable for garden growers too.
The book also takes the stress out of GYO, and explains about things like sowing and harvesting times are not cast in stone.
And finally, it's really well written and easy to understand.
I would recommend it strongly to anyone starting out, as well as anyone who thinks they know it all!