4 x 10 Book Challenge

I have been inspired by Meredith at Sweetness and Light (who got the idea from Painted Rainbows and Chamomile Tea) to take up this challenge - read forty books, four in each of ten different subject areas. The aim is supposed to be to read them in a year, but I'm looking for a fun way of structuring a reading list and not to put myself under pressure, so I'm not going to give myself a target. They will get read when they get read.

I'm working on my list of books, and will post it later.