The Future of Money by Bernard Lietaer. The best overall introduction to the field. Shows the relevancy of ‘complementary’ currencies to big issues such as ageing populations, climate change, technological progress, etc. Inspiring ‘big picture’ stuff. See also www.transaction.net

Healthy Money, Healthy Planet by Deirdre Kent. Excellent overview of the mainstream money system and the emerging alternatives.

Money - Understanding and Creating Alternatives to Legal Tender by Thomas H. Greco Jr. A more detailed introduction to the history and relevancy of community currencies. See also www.reinventingmoney.com

The Money Changers by David Boyle. An entertaining and informative romp through the highways and byways of monetary history, monetary reform and monetary innovation.