1. Get outside lighting for at night, I suggest the new LED lighting, because it uses a lot less power to run.
2. Get some type of fencing (even if its just a picket fence) to make a barrier so as the bad guys know their is a boundry that if they cross it they could be shot.
3. Some type of motion sensors, cheap ones work great.
http://www.northerntool.com/shop/to...17?cm_sp=Upsells-_-Top Sellers-_-Product Page
4. Cameras, at least 4 cameras and a screen to watch them on. Have the screen in a room that is away from what you consider the most dangerous side of the house or where threats will come from.
5. Keep 3/4 inch plywood on hand for windows that are down stairs and windows that are on the side threats may come from.
(This is for after the SHTF).
6. Make sure you have a gun hidden upstairs and downstairs and thru out the house that you can get to quick. This is if you don't carry one on you at all times. However you could be in the house, and forget to strap on your gun and thats when you will need one the most.
7. Have a safe room, A place for everyone to goto incase of a home invasion. This room should have a solid door and a steel case so as it can't be just knocked in with a single kick. Also no outside windows if possible. Have a gun hidden in this room espescily.
This room will provide a little security, while you figure out what to do to get the invaders out of your house.
8. Have extra 2X4 and 2X6 boards and Plywood for security projects you may want to do after the SHTF. If you can get it and store it get some 4X8 sheets of sheet metal that are as thick as you can handle by themselves.
9. Get a dog, however this will be an extra mouth to feed, so have plenty of dogfood on hand. Get a german shepard or a doberman or smaller breed aggressive dogs, so they don't eat alot of food. I am against pit bulls, because they seem to be too aggressive.
10. Get a home alarm that will alert you if a window or door is open. Have a loud siren inside and outside to help scare the intruders. Or to alert the neighbors if you get the number 11 tip setup.
ETA:
11. Get a form of communication setup (walkie talkies) and see if your neighbors would like to get involved in a neighborhood watch if the SHTF. This may be something you might want to setup after the SHTF if you don't know your neighbors good. In that case have enough walkie talkies to hand out, that can communicate to each other, Remember there is safety in numbers.
Neighbors will be great allies if the SHTF, unless you have the bum neighbor that can't even feed his family now, much less after the SHTF.