Well I've made my choice: Reading Like a Writer by Francine Prose - a book I first came across through Debra Hamel's blog.
I did start reading it last night and liked it. She says that every writer learns how to write mainly through what they read and how they read. She said that a writer notes how a book is written when they read - the voice, the point of view, how the sentences work with each other, the word choice and so on. This, I think is true. I remember discussing point of view with my former agent and she told me that she was never aware of the point of view, or which 'person' is narrating the book (first person, third person, omnicient narrator); she was just aware of the atory. But how a story is written fascinates me and I always take note as soon as I start reading a novel: why choose first person, for instance, or do we follow just one person throughout the book?
Another point I find greatly reassuring: she says that, unlike some authors, she never feels she needs to give up reading other people's books when she is writing one herself. Rather, she says, she feels inspired by her reading, and feels it improves her own writing. This is something I've always found myself. She says that if she'd had to give up reading when she was writing (which is, after all, an almost continual process) she doubts she would have been inclined to write that much at all. It's such a great feeling to discover that I'm not alone.