You want to survive a Zombie Apocalypse? You will do as I say and you may just live to tell the tale.
Of course that's based on the theory your zombie apocalypse scenario has an ending. Most zombie apocalypses(apcalypsi?) are end of all things kind of zombie scenarios. George A. Romero's great epic Living Dead series presents that the world is so overrun with zombies and all who die, not just from being bit, rise again. That kinda puts into perspective that life is over and there's no chance for a tomorrow.
But first we have to establish the basics to survive a zombie scenario. We have to figure out which category it fits into, or rather what kind of zombie are we dealing with. Now, for a zombie apocalypse, it would have to be the living dead not a mindless, voodoo controlled, being. I'm fairly sure we can get past living zombies with ease compared to the undead. Now when presented with a zombie apocalypse, I ask myself the following questions:
1. What category of Zombie attack is this? What begat the zombie plague you are facing?
* Biological - A virus or some other biological means that has made the dead rise, and spreads a contagion that converts living tissue into zombie. Also included in this would be radiation affecting the biology of a living person turning them into a zombie.
* Chemical - A chemical compound has reanimated flesh, and even the seperation of the brain will not stop the body from functioning as it is reanimated not alive.
* Metaphysical - No explaination can be found. Death has simply stopped caring and sent everyone back. Perhaps the afterlife is full, perhaps an evil spirit in the woods has awakened, or maybe God just hates you. Either way, the dead are just rising and killing. Now, metaphysical just rising dead can also just rise and not be psychotic killers but rather just regular joes, but the more the brain has decayed the more likely it is they will kill.
2. How do you kill your zombie? To survive you will have to kill at least one.
* Brain Death - "Just shoot them in the head" Any kind of injury to the brain or spinal cord will have the same effect it will on a normal person. Body goes down without any functions.
* Full Body Death - The brain is gone, head is gone, spines broken, the flesh is still alive. You may just have to completely dismember the corpse or burn it. But with burning you risk the contamination of zombie ashes.
* Rare but always possible "Just shoot them" death - The reanimated corpse can be killed as easily as the first time it died. No special means, heck you could choke the sucker out.
* The even rarer, "Special Means" Death. You may need to kill your zombie via some form of magic or special agent that can break down the zombie's reanimation process. Perhaps a particular metal will just stop the reanimation, if so just hit them with that. It is very rare that your zombie will need to be taken down in this way.
3. How does the future look? Is there a chance for a return to normality?
* Biological - In the biological category, a cure is usually possible. A gene may exist in some people that prevents the viral agent from taking over or perhaps the virus is only temporary and the immune system can kick it out. Maybe the zombie can starve to death? Maybe chemo works? In the biological case, it's usually a good chance for normality to return if you survive.
* Chemical - This too generally has a cure or at least an antithesis to the first chemical. A way to break down whatever has reanimated the dead. But many times it's likely whomever invented the reanimation reagent dies before they figure out the antidote.
* Metaphysical - This is tricky. Depending on what metaphysical manner has risen the dead, you have a chance or you might as well just give up. Evil spirits? Containable. Afterlife's full and the dead are just walking around with nowhere to go? Managable. Dead just rising? Might want to just hide out on an island until you die of old age.
Also always take into consideration wether or not animals are rising too. If a mosquito is a zombie then you're probably screwed.
Now once those questions are answered, you would then have to think of how you survive. Where are you? An isolated area? Populated city? What do you have available to defend yourself with?
What you have to do in most cases is find shelter, and wait it out. I recomend the Dawn of the Dead scenario more than anything. Board yourself up in a mall, you will more than likely survive in comfort there. If you can't find a mall, any kind of department store will do, especially a Wal-Mart. In an isolated area? You have the best chance then, you have days before any serious number of zombies come for you. You can fortify your defenses, and prepare for the onslaught.
The ideal place to hide would be an island. Rigor Mortis, decaying flesh, and water do not mix well. Even if the zombie can get into the water, chances are they won't be able to just walk on over to your island and even then, the water weight will make them easy pickings.
But let's talk a mall, or department store, the most likely area to hide and survive:
Inside you will have food, shelter, fresh clothing, weaponry, and defendable terrain. It should be no hard concept to figure out how to defend yourself inside one of these places unless there is no power. Which is a possibility but there's also a good chance wherever you are will be selling generators and flashlights anyway. The first thing you have to do once getting to the safety zone of the mall/store is to find and seal off all entrances and exits. Anyway outside needs to be covered. Doors, windows, fire escapes, perhaps a tunnel system underneath leading to a parking garage. The Parking garage will be the worst place you can find, if possible you will want to collapse the parking structure somehow. Make sure it does not damage the building in any accessible way. It would be ideal if you could just collapse the garage and seal off exits without any problem. Realistically, you may need to just move some cars around. No keys? Red to yellow or yellow to blue, or just stab the keyhole with a screwdriver. Move the cars as close as possible to the entrances and exits, if the parking garage is secure and you have found no zombies, I recomend moving all the cars into blocking off the first floor and main entrance. Rig some to blow up if necessary.
Once the parking area is secure, lock all the doors. Seal them as much as possible. Cement, weld them shut, brace them somehow, anything to make sure nothing can get through. Now here is the tricky part, you will want one or two emergency exits for the just in case scenario. Never should they be on a ground floor. A rooftop, second or higher story window, basement access, or if possible, the loading area. A loading dock area should be big enough to hold some kind of vehicle inside, store it just in case, and seal the big metal doors, they won't get in but you can get out if you need to.
Once your building is secure it's time to arm up and set defences. You will want guns. Swords and axes look cool in movies, but suck in close range zombie fights. Blunt objects are ridiculously unsafe too. A gun is what you need. The shotgun is superior in it's ability to easily remove the head, but for most people it's impractical. A shotgun does not hold many rounds, it is not accurate, and the kick may be a bit much for some. A handgun, 9mm or so, works just fine and accuracy can be easily improved upon. Automatic weapons are probably the best line of defense you can have. The rapidfire sound may even scare zombies away as opposed to the one shot sound. They too can easily remove a head and hold much more ammunition. Remember to stock up on ammo. You will run out during an attack, you will have to reload. You cannot just fire a shotgun over and over without reloading.
If you are forced into a close encounter fight you will want the supreme zombie fighting weapon. The Chainsaw. Use it. Embrace it. Make it part of you. Never let it into the wrong hands.
Which brings me to my next point. Beware of how competent your zombie is. Fresh zombies have not been hit with rigor mortis, they will be fast and wild. Some can even retain knowledge to use weapons and tools. There is a chance you could encounter the rare but possible, smart zombie. No rigor mortis, still aware of himself, but also crazy and hungry. He can still fire a weapon and dodge a bullet. Most undead zombies will stand there and take the shell to the head, this one will dodge and try to fight the gun away from you.
If you can maintain your weapons, hold your defenses, and wait out until help comes, you may survive a zombie apocalypse.
But be warned, there is one scenario deadliest of all. The Lovecraftian Frankenstein Zombie scenario. By pure chance, you might be encounter a reanimated corpse made up of multiple corpses to be some form of super soldier. If may even have animal parts to give it an edge. Chances are you won't be able to take this bastard of science down with a bullet to the head at all. With these things, it has to be fire or electricution. Something to really damage the flesh.
Keep your nose clean, be alert, always carry extra ammo, never go out alone if you can avoid it. Try to find a group to survive with, being trapped alone may drive you mad. And remember, always run from zombies if you can. Do not stand your ground, they will eat your brains.