When using extension cords to run a device in your home do your best to make sure that this is only a temporary solution. Extension cords can be a great thing but they are also easily disconnected and can be very unstable for both the item attached or as a tripping hazard. It is just best to plug whatever it is that you are using into the wall if possible.
When putting wire or cable and running it from one place to another; always be careful. It is never a good idea to hold these items in place with nails or staples as hey can easily cut through the insulation on the wire leading to corrosion, shorts or even fires. If you have to use wire clamps or tape to hold these items down and in place.