I was really impressed with this book. It covers every vegetable you could want to grow in enough detail. He even includes some I've not heard of and I'm a very experienced grower.
There is a useful section on what to do each month and tables giving optimum germination temperatures etc.
There are some lovely photographs in the centre but make no mistake, this is a serious book not some coffee table job dreamed up by a marketing department. It's the sort of book you read and then keep handy as a reference work.
If you're thinking of growing in a polytunnel then order a copy, if you already grow in a tunnel then I bet you'll improve your technique by reading this.