i was watching fox news last night and they had two detectives talking about how to prevent a home invasion. they said "first off, always use your garage to enter/exit your vehicle if you've got one...and only when the garage door is closed." "next, get a dog. Dogs can sense evil and will let out a very distinctive bark when something bad happens." In the nicole brown simpson case, her dog was still barking ferociously at the front door when the police arrived long after the incident occured, IIRC.
I had a neighbor get broken in to by his daughter's friends once, their dog had seen the kids before but new something wasn't right. The female 10 year old german sheperd wouldn't be quiet. I looked next door and saw a bunch of kids entering the house at 4 pm. I didn't think anything of it since they were regulars.... they robbed her dad for some black powder rifles and a 10 key calculator and trashed the place. Police later caught them. I felt bad for cussing at the dog when it happened.
Also, take your wife and kids shooting! give them a chance to defend themselves and they may just enjoy the sport. Get them out shooting clays with 20 gauges if you have to, just get them used to guns so you're not the only one who can use anything out of the safe if you hear a window break.
Set up a plan of action. Get a 'safe place' designated, such as a trusted neighbors house in case there's a fire or their is a home invasion and you can get your kids out a window or something. The neighbor will know that something horrible happened if your 4 year old shows up on the porch out of breath and unable to compose a sentence if they know that they are the safe house before they show up.
Be sure you teach your kids how to get out through the windows (using a ladder if on floor 2) useful escape that too few facilitate when necessary.
Remember, drywall will not stop any home defense round of ammunition. If you know you've been invaded and you are sure it is an invasion, start shooting through drywall. The element of surprise will save your life. Also, remember that you're a good guy, they aren't. If you're human you will hesitate before taking a life, it's part of what makes us good guys. Bad guys will not hesitate, they want you out of the way first thing or they would not have invaded a home that was occupied.
A home invasion occured a few years ago in Wichita, KS where the Carr brothers invaded a party of 6 young adults in a nice part of town. They were out looking for a victim that evening before they brutally raped and murdered 5 people, and shot a victim in the head with a .380 who later ran naked in the cold across a busy highway to help.
This is my opinion, and I've spoken to my wife about it, I will not be a sheep if there is a home invasion. whatever their weapon, I will no cooperate, and during a hostage situation I will not drop my weapon. This is my personal plan of action, and I go through it in my head all the time and I see this as the best option. There's some things in life that are worse than death....and seeing thug kill your wife and children would definitely be one of them, I don't want to live to regret not doing something...no matter how futile.