I recently did a public presentation on rain barrels at an environmental education event sponsored by North Richland Hills.
Instructions (revised 5/31/09)
Parts list (revised 5/31/09)
Here’s a video of an alternative design that is simpler. I like the design except that I find the overflow a bit obtrusive without the elbow.
And a video of a third design. Few details given, but the overall picture is instructive.