The Art Of Indonesia, by Frits A. Wagner, Greystone Press, NY, revised edition, 1967. A dated, but still classic, survey.
Art Of Indonesia: Pusaka, Periplus, 1998. Meandering essays but good large-format photographs from the collection of the National Museum in Jakarta.
Blue Guide: Bali, Java, and Lambok, by Gavin Pattison.
A&C Black, London, and WW Norton, NY, 2000. This book is now out of print, and contains less site-specific information than other books in the Blue Guide series. Nevertheless, it still serves as an introductory cultural guide to Indonesia.
Borobudur: Golden Tales of the Buddhas, by John Miksic, Periplus, Fifth Printing 2000. An excellent guide to Borobudur, with comprehensive photos, essays, and descriptions.
Cultural Sites of Malaysia, Singapore, and Indonesia, Jaques Dumarcay and Michael Smithies, Oxford University Press, 1998. This book concentrates on architecture, with many black-and-white photographs and axiometric drawings. However, it is oddly lacking in basic data such as site plans and numerical dimensions.
Icons of Art: The Collections of the National Museum of Indonesia, BAB Publishing, Indonesia, Second Edition, 2007. A well-produced survey of the Jakarta museum.
Indonesia: The Discovery Of The Past, KIT Publishers, Amsterdam, 2005. The catalogue of a joint exhibition that temporarily reunited some important objects from the collections of Amsterdam and Jakarta. Most of the essays in this book are of museological, rather than art-historical, interest.
Island of Bali, by Miguel Covarrubias, Alfred A. Knopf publishers, 1946/1973. A dated but still relevant cultural history of the island, including anthropological data and photographs.
Monumental Bali, by A.J. Bernet Kempers, Periplus, 1991. A useful guide to the monuments of Bali.
The Sculpture Of Indonesia, National Gallery Of Art, Washington, DC, 1990. The catalogue of an important exhibition of Indonesian art, with informative essays.
A Short History of Bali: Indonesia's Hindu Realm, by Robert Pringle, Allen & Unwin, 2004. A good brief history of Bali, with references and notes.