Burnham's Celestial Handbook: An Observer's Guide to the Universe Beyond the Solar System (Volume 1)
This series of three books contain the most precise information in a usable form for the amateur that I have seen. A classic series that would be almost impossible to duplicate. Although limited to 1950 co-ordinates for celestial objects this does not detract from the usability of the information contained within the pages. Clearly and consisely written, with background information as well as clear descriptions of the objects listed. The books could have constellation maps, but since I use them with a star atlas this would be a luxury.