Brad Lancaster, the Watershed Management Group, and Tucson are all doing incredible work with rainwater harvesting and education. I highly recommend these videos from Brad Lancaster:
Rain Gutter Installation
Rain gutters are a valuable system for your home as they allow you to direct that vast amount of water away from falling all around your foundation and instead toward one or two select spots along that roof. Then you can design for adding rain tanks, dry creeks, infiltration basins, and more with much more ease and impact.