This is a guide to get yourself to a point that other players might just start to fear you. With that said, I am not going to condone raiding, and will be giving the non-violent alternative. If you wish to raid, there's a small section at the bottom (since it incidentally will be viable if you follow this guide).
This guide is recent as of the 18th of December, 2013.
Before you do anything, like searching for nearby rocks or trees, take a good look around. Try to find a road, animals, or preferably a server-generated structure. Animal spawns are extremely important when first starting, as it gives you cloth to manufacture a respawn point and some starting armor. Mutated bears and wolves provide a good variety of stuff, from armor, food, blueprints, and even explosive charges.
Server-generated structures are extremely useful as well, since it can help you skip entire tiers of build-up without needing to find stone. How, you ask? You'll need to find crate spawnpoints. See the town scavenging section for more information.
First things first: You need a respawn point, and it needs to be relatively safe. Hide it in some mountains after finding the spawns you like, and make sure there's no one within a few seconds' walking distance. The amount of materials you'll need are 15 cloth and 80 wood (Sleeping bag, wood shelter, wood door). After that, it doesn't matter if you die of starvation or something, so long as your base is hidden. For safety, do not place a campfire or a foundry anywhere near your shack. Light attracts the wrong kind of attention.
With a spawn in place, you can start on scavenging, hunting, or what-have-you. If you do not have any guns, I recommend scavenging in as little stuff as possible. The less you lose per excursion, the better.
This is a (mostly) safe way to get just about everything you need. For the safest farming, try to remember the more irradiated areas from the less, and book it when you think you're going to exceed 500 without any sort of radiation reductions (for best results, radiation pills).
Zombies have a wide variety of goodies if you can drop them. If you don't have a ranged weapon, it's best to run from zombies. A safe way of avoiding zombies in town is to run into buildings, since zombies currently can't follow. Stay away from the walls if you choose to do this, as they can attack through them.
If you use a shotgun or a pipe shotgun, it takes 1 good shot to kill the normal or red variant, and it takes 2 good shots to kill a black variant. A "good shot" is accomplished by holding down the right click to scope, then aiming for the upper torso to head and firing when it's directly on you, so all bullets hit their mark. It takes some practice, but once you get it down, farming zombies nearly triples the amount of scavenging to be had in an area.
Crates come in 4 or so shapes and colors, each depicting what it may have in there. Spawn points do not have a color hard-locked, but the spawn points do not change position and are not affected by over-farming. They're merely on a 5 or so minute cooldown after despawning (which occurs when everything is taken from it).
It doesn't matter what color you find, they're all good. But as a quick reference:
1) wooden crates gives you: ammunation, cloth, metal fragments or food
2) Red gives medical supplies (rad pills, large/small health packs) or bleuprints
3) Green gives weapons, ammo, mods or research kits
4) Yellow gives ammo, mods, bleuprints,or armor. This armor is usually leather or rad suit.
For scavenging, crates what you're looking for. The larger the town, the more spawn points there are to be had. I can't remember which color, but you can get metal fragments from these crates (approximately 15-40), which means you can easily craft a metal hatchet with a single scavenging run.
If you're in the town just to scavenge (not hunt zombies), it's best to avoid these other players. They'll probably try to kill you and even nudists can have guns in a town. You can voice that you're friendly, but as soon as one starts following you, chance are you'll need to kill them or run, depending on whether you have a gun or not.
When you're hunting zombies, just state that. Usually other people can respect that, and since you're toting around a loaded weapon, you'll only have problems if they're sociopathic or in a group.
The long run
Try to keep some radiation pills as back-up, taking no more than 10 into a scavenging area at a time. If you find a large supply of them on your run, consider leaving early. What you don't want is to run out of pills because some guy took a shotgun to your back and you lost them all.
While wearing a full radiation suit means you need to take even fewer pills, it's best to use only one or two pieces of rad suit equipment. It goes down slowly enough when you're chomping pills, and with 2 pieces of leather you won't die nearly as quickly to melee or light weapons fire.
Collecting outside of townsEdit
Good luck with that, really. Between stone nodes being as rare as they are and most resource spawns being a pain to find, your best bet is waiting for the server to go down for temporary maintenance. When this happens, all of the "linked" resource spawns are refreshed, making it possible to actually find stone or wood piles in decent amounts. Unfortunately, the alpha does not appear to do a very good job at figuring out how to respawn other resources more when there's a run on one type (everyone goes for wood, stone won't spawn more often, etc.).
A good way to gauge how good spawns are in an area is to check the trees. They are partially linked in that they'll give less is a place is dry, or more if it isn't. On a fresh server, each tree will give approximately 12 wood before locking out. On a resource-dead server, each tree will provide between 7 to 9 (9 is favored). Stone nodes tend to spawn in groups of 1-3, 1 being a large stone and 3 being 1 large + 2 small.
Building a baseEdit
If your shack is hidden well enough, it's best to decide at the start of a gaming session that you'll be building your base. Go out and keep collecting any wood you find, and convert it into the necessary dimensions for a base. The toughest part of completing a base is the metal door (200 fragments), and for the best results, you're going to want at least 2.
Collecting the materials
Always pick up wood piles, it's essentially 80 tree hits that only takes 8. In case you're wondering, you do not need to make foundation for each floor. Pillars can be placed on pillars, and ceilings are effectively floors since it only checks for pillars on most wood structures.
Choosing a spot
While I'm sure you've seen and heard it several times already, the best position is one that nobody will come across. While it's nice to have a tower in the middle of a field, that tower is going to get blown up and invaded. You're not going to be able to keep any materials inside safe from a large enough group of raiders, unless they have no idea that it exists.
There are two major ways to design a base. The first is to build a straight-up house, one with walls, roof, floors, stairs, and rooms. The safest design for this kind of structure is as many rooms and layers as possible. When a raider is raiding, they'll be less than willing to blow through 6 walls/doors when it's shown to be a waste of explosives. If the outer wall is three layers thick, it means they need 6 charges just to look inside. If you divide up the housing with a bunch of rooms, it means they gotta burn 2 more charges per room to go through it all. Even if they break down all the doors, it'd be more costly than just about anything you can store in there.
The other method is to invent alternative methods of moving through a structure. Instead of stairs, use a large wooden box and an open door to reach the next story. If they break the door, they can no longer get up without making a new one. If you don't want anyone on the next story, open the door in the wrong direction and people'll scratch their heads on how to move up.
Instead of simply making a doorway, require a player to die and have a spawn on the inside to get in. Leave a pathway to reach their corpse after respawning and a little jump down to get back out, then it becomes a nightmare to invade. If they do choose to break in, they won't be breaking anything valuable (wooden walls are just as strong as metal doors, but they take a measly 40 wood to rebuild).
Hiding a doorway behind a staircase, requiring the player to kneel under it to get to the other side, is actually a very viable method of preventing invasion. In a closed environment, explosive charges can damage the would-be raider while they're trying to run away after setting it. Throw around enough obstacles to getting distance and they'll most certainly eat the explosion.
On top of this, there's the loot layout that needs to be taken into account. I know you want to divide everything into their own rooms, boxes, and so forth, but that design is putting all your eggs in one basket. Someone gets to that spot, and you're done. Sure, a gun-room sounds awesome. So does a crafting room. But if it's broken into? You have no more guns even though that was the only room they cracked. You can divide up the loot evenly so you're guaranteed to lose a median percentage per room broken into, but that could take a lot of boxes. So what's the best way?
I recommend placing "dummy" rooms. Your base can have a ton of rooms, but plop down a bunch of storage chests with nothing in them in all the spots you believe someone will break into first. When they break through, they're going to be put off more than a little when they see your "obvious" storage room has nothing of value in it.
If you really want to raid, I'm just going to mention here that zombies can rarely drop explosive charges. You need 2 to break down any metal door (the info page claims it takes three when it's fresh, but that's just not true at this time). A good way to start is to find some group that's got a decent place set up, collect about 4 explosive charges, and raid when they're offline. Kill any offline player you see, destroy any sleeping bag you find, loot anything and everything (especially more explosive charges).
Try to target someone with notably more stuff than you, as they've got the best chance at having explosives (the material). If you can find explosives, you can use a research kit to be able to craft them yourself, meaning you can raid anywhere, anytime. So long as you can collect the parts.