I bought this book. It's a good read, with lots of photos, to help me dream of summer days...
I've found the most useful bit is the section on "growing the right amount of the best varieties".
Most of the information is quite similar to other allotment books (I'm thinking of the one by Andi Clevely, which I also bought). No idea yet if the advice is useful, as I've not long taken on half an allotment and I'm more or less sorted now for winter. Roll on spring...