Books
New books on rainwater catchment are coming out all the time. Here are a few available from Amazon.com and other sources.

Rainwater Harvesting for Drylands: Guiding Principles to Welcome Rain into Your Life And Landscape
Brad Lancaster

Design for Water: Rainwater Harvesting, Stormwater Catchment, and Alternate Water Reuse
Heather Kinkade-Levario

Rainwater Catchment Systems for Domestic Supply: Design, Construction and Implementation
Erik Nissen-Petersen
& John Gould

Water Storage: Tanks, Cisterns, Aquifers, and Ponds for Domestic Supply, Fire and Emergency Use
Art Ludwig

Rain Gardens: Managing Water Sustainably in the Garden and Designed Landscape
Nigel Dunnett
& Andy Clayden

Helen Kraus
& Anne Spafford