Which Narnia book corresponds to which planet?

In case people haven't heard of it, there's a brilliant theory which suggests that each of C S Lewis's seven Narnia books corresponds to one of the seven 'planets' of pre-Copernican astronomy (the Sun, the Moon, Mercury, Venus, Mars, Jupiter, and Saturn). For more details see here.

I've been trying to work out (without going out to spend a tenner on Michael Ward's book!) which 'planet' corresponds to which Narnia book. Some nosing around the Planet Narnia website turned up only one correspondence:

• Jupiter <--> The Lion, the Witch, and the Wardrobe

I also remember that the 'Old Father Time' who appears asleep in The Silver Chair was Saturn in an earlier version of the book, and that this was used as evidence for:

• Saturn <--> The Silver Chair

Since the main aim of the eponymous characters in The Horse and his Boy is to deliver a message, I would also guess:

• Mercury <--> The Horse and his Boy

What are the other four correspondences? A simple answer backed up by a link would be great, but some explanation for how all seven correspondences match up (things like (Horse & his Boy) -> message -> Mercury) would be even more appreciated!