From the reviews:
Mullaney packs an incredible amount of information into this 166-page book. ... 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. (Michael Bakich, Astronomy Magazine, October, 2007)
The Herschel Objects and How to Observe Them is a fine addition to the Springer series of observing guides. Mullaney has been observing the Herschel objects for many years and his passion for them clearly comes across. ... Overall though, this is a book that will be a useful addition to any deep-sky observer's library. (Paul Money, BBC Sky at Night, February, 2008)
Mullaney begins with a well-written biographical sketch of Herschel and his family, and explains the significance of the work of this great observational astronomer. ... the objects are illustrated with excellent images obtained using a modern charge-coupled device (CCD) system. The book concludes with a list of 618 targets that would provide for a lifetime of study. The book will be of greatest interest to experienced observers who wish to push on to the most challenging deep sky objects. ... Summing Up: Recommended. General readers. (D. E. Hogg, CHOICE, Vol. 45 (6), February, 2008)
The book opens with a few short chapters on Herschel himself together with a brief introduction to observing techniques ... . rounded out with some objects that the author regards as showpieces that were not discovered by Herschel. Any collection of these will of course be very subjective. ... I found the book's reproductions to be a cut above the usual Springer ones and the book does offers something sufficiently different ... and the Astronomical League guides to make it worth adding to your collection. (Owen Brazell, The Observatory, Vol. 128 (1203), 2008)