books for beginners

Other than Turn Left at Orion, what are some other great books for beginning deep-sky observers? I'm interested in more than just an observing guide or how-to...I'd like some in-depth information about what exactly it is I'm looking at, how it formed, etc. Thanks!
clear skies and good reading,
doug

In additon to 'Orion,' I also started with the Peterson Field Guide to Stars and Planets and Audubon Society, Field Guide to the Night Sky. I also recommend 'Touring the Universe Through Binoculars,' and 'Starware.'

Later, think about The Night Sky Observer's Guide.

Good Luck, Pete