Werner Backes, Drachen einfach und schnell gebaut, 64 pages, ISBN 3-473-45680-2 (german)

A small book on kites which are cheap and easy to build (wooden spars, garbage bag sails, etc.). It focusses on building single line kites - the only dual-line kite is a basic Eddy stunter. The plans are sufficiently detailed and seem reliable...like in all of Backes' books.
This is a good introductory book.