Good Book on Canon 40D and digital photography

I am looking for a good book on the D40 so that I can learn to make the most of all of its features, and also improve my photography to a higher level.

I already have a good basic understanding of digital photography, aperture, shutter sppeds etc but want to learn everything thats possible with a D40 and learn how to maximise the use of the settings in diiferent situations, and different types of photography.

Does anyone have any good recommendations?

Thanks