We aren't supposed to have them here. Biggest campaign of BS I have ever heard of. Basically, the idea is that the rain water is supposed to go to the aquifer, and not into storage to be used for whatever. Ridiculous part is that if you water your property with it, then it is sort of going to the aquifer anyhow, your just delaying it, which could be a good thing.
I have two 50 gal barrels in my back yard. My house does have gutters. I cut a ~2ft section out of the middle portion of the down spout and inserted one of those flexible water diverters that are designed to go on the end of the down spout and extend/direct the water away from the foundation. My barrels set next to the down spout, after it has been raining for a bit I go out and open the barrel and divert the water until they are full.
I use it primarily for my blueberries.
The first barrel just sits flat on the ground, I also thought that the hydrostatic pressure would be enough in the barrel to make the water flow well. Live and learn. I have a short hose to fill the watering can but it is slow to fill. My second barrel, I built a stand about 18" tall out of 4x4" cedar timbers. I hand water my blueberry bushes with a 2 gal watering can, so the second barrel is nice because the can sits about 4" below the spigot.