This article is from the Calendars FAQ, by Claus Tondering claus@tondering.dk with numerous contributions by others.
This is a big question because there are so many excellent books. At
this point I shall only recommend two books:
Edward M. Reingold & Nachum Dershowitz: "Calendrical Calculations.
The Millennium Edition". Cambridge University Press 2001.
ISBN 0-521-77752-6.
http://emr.cs.iit.edu/home/reingold/calendar-book/second-edition/index.html
This book contains a lot of information about a huge number of
calendars. As the title indicates, it has a strong emphasis on
algorithms for calendrical calculations, so if you want to use your
computer to compute calendars, this is a great book.
R. W. Bauer: "Calender for Aarene fra 601 til 2200". First published
in 1868. Reprinted 1993 by Dansk Historisk Faellesraad.
ISBN 87-7423-083-2
Unfortunately, this book is in Danish, but if you can read the
Scandinavian languages, this book will provide you with a wealth of
information, despite its age. Its main strength is a huge collection
of tables of various calendars. It does, however, only describe the
Christian calendar.
 
Continue to: