Depending on the power reliability in your area, preparing for a power outage is as important as water changes. You can purchase a battery powered air pump, or a 12v DC pump that you can hook up to your car battery if you need some serious circulation.
Unless the power goes out for longer than a day your fish should be fine, depending on your stocking levels. Your plants should be fine for a week or so, but if you have any tender plants, they might suffer when temps drop down.
In my area the power never seems to go out for longer than 4-5 hours. I have never needed to take my 12v pump out of it's box. But I am still glad I have it.