Stars and Galaxies
David Eicher, he discusses the main galaxy groups, the nearest galaxies to us, the best clusters galaxies,and nebulae in the sky and lots of glossy pictues, well laid out. 

The Universe from Your Backyard
David Eicher, An easy to read list of all the best deep sky objects, done for each constellation. Lots of glossy pictures and maps.

The Deep Sky, An Introduction
Philip s Harrington, this book goes though what there is to observe, how to do it and then goes through galaxies, clusters and nebulae on a per season basis.

Seeing The Deep Sky
 Fred Schaaf. Over 200 pages, paperback. About observing extra Solar system objects, giving the reader projects and assignments to work through.

Deep Sky Observing 
( The Astronomical Tourist ), Steven R. Coe.Very practical book, though not totally comprehensive. It is written by an amateur astronomer, who is quite charismatic and human, and gives you a realistic idea of what nebulae will look like in a 6inch, or 13inch telescope. Forget the pretty Hubble space pictures.

Celestial Sites, Celestial Splendors
Herve Burillier. A little paperback, printed in 2000 translated from the French. 100 of the best deep sky objects, always giving a little sketch of what an 6 -12 inch scope might see of these objects. Nice little encyclopedia, very pocket sized. Nice to have with you.

Space Watching 
( Advanced Sky Watching ) D. Levy. Great pictures throughout, though a  little disjointed perhaps.

The Sky
A User's guide. David Levy. Great anecdotes and stories throughout. Not many pretty pictures, but great easy-reading on how to go about practising amateur astronomy.

Deep-Sky Observing with Small Telescopes
David Eicher, a good staring off book for someone wanting a one fits all solution for anyone with a small telescope, it covers deepsky objects by catagory and includes a list of double stars, an old book these days, but still useful.

Galaxies, and how to Observe them
Steinicke, Jakiel. A guide how to go about observing galaxies, equipment you need, what kind of galaxies are out there and the clusters they lie within.