We came across a simple list of 20 things you can do for free to save energy. While we're not always a fan of Consumer Reports because there are plenty of reasons to go green regardless of what it costs, it's hard to argue with free! The list is reasonable and motivating -- and a good example of how to explain "green" in just a few words.
For us, most of the suggestions are rote: use a clothesline; when you don't, take clothes out of the dryer while they are still damp; turn your thermostat back 10 degrees when you leave home or tuck in for the night. They go one step further, though, by explaining just how much energy most of these steps save. Setting back the thermostat? That's good for 20% off your heating bill.
So it's not revolutionary, but that's not the point. It's a great resource if you're trying to green a friend, parent, or grandparent. Check it out over at the Consumer Reports; most of the site requires a paid subscription, but you can get to the list for free.