Springer
The definitive work on a famous list of deep-sky objects is now in print: The Herschel Objects, and how to observe them by James Mullaney (Springer, 2007). Why definitive? Because, in 1976, Mullaney was the first to propose an observing list based on Herschel's catalog.
Mullaney packs an incredible amount of information into this 166-page book. He gives us a brief history of English astronomer Sir William Herschel (1738–1822), a list of the telescopes Herschel used, and the astronomer's cataloging system.
Herschel compiled a list of some 2,500 deep-sky objects he observed. Most of them had never been seen before. He divided his objects into eight classes, six of which contain, according to Mullaney, 615 showpiece objects. This was the number Mullaney originally proposed as an observing program, but the "final" (until now) list numbered only 400 objects.
Mullaney lists his 615 Herschels by classes and constellations. In Appendix 3, he tabulates them in each class by right ascension. That section makes a nice roundup as well as a checklist.
Mullaney includes a chapter called "Observing Techniques." This is a must-read for new observers and a near-must-read for seasoned observers. Don't take this the wrong way, but few of us have as many hours at the eyepiece as Jim Mullaney.
I especially enjoyed chapter 12, "Showpieces Missed by Herschel" and chapter 13, "The ‘Missing' Herschel Objects." In chapter 12, you'll find standout celestial targets Herschel never observed. Too bad. He would have waxed eloquently over the Helix Nebula (NGC 7293), the Pacman Nebula (NGC 281), and the Rosette Nebula (NGC 2237).
Chapter 13 makes a great read if you, like me, are into astronomical history, especially where it overlaps observing. Mullaney also presents a list of 30 "missing" Herschel objects you can sleuth out in the sky.
All in all, The Herschel Objects, and how to observe them is engaging, challenging, well-written, and comprehensive. So, if you love deep-sky observing — and even if you've observed the Astronomical League's Herschel 400 — Mullaney's book offers a new list with several hundred additional objects you'll enjoy.