This answer could be pages long. But I will answer a couple of your basic questions. Individually we will not make a difference, it can only be a difference if all of society makes the changes. Unpluging one charger (or appliance when not in use) does reduce the amount of energy used, but if a million people do it, then the amount of energy saved is a million times more. Paper is definitely better than plastic, because paper is recyclable and breaks down in the environment quicker, but the best choice is bring your own bags. And driving with the windows down gets much better mileage than with the AC on (check out Mythbusters on the Discover Channel, they actually did this experiment).