In this thread I will help you to get what a villager needs and how to do it.
I will post here some hint's and other importand stuff, and all the requirements.
Hints for when you first arrive at your village:
-put doors in all houses which don't have doors!
-place a lot of torches on the building and some on the surrounding area, so less monster/zombie spawn.
-close over the next days possible earth holes, so villagers don't run accidently down, they will not find back on their own!
Generel hints for more villager breeding:
-Build more houses
-Build more doors into excisting houses (like a backdoor)
-expand the village (houses further away from each other) over 60-100 tiles.
-Build your own house close to the village so your house count's for them too
-secure them a bit with fences, walls, so they have a area where they live in. Makes it easier to controll breeding too.
-Villager kids appear in brown robe only after birth till the first save/quit. After the next load their profession will be updated and they get their final robe.
Hints to secure your village population and letting them stay in your village:
-force 2 villager on a roof, or build one cellar and place 2 there, or place them in a cauldron. With this you have allways 2 villager secured which breed back the population if yours get lost.
-Although villager tend to go where other villagers are duo to their socialise behaviour! So if you let some stay in a certain area, other villagers will try to stay near them and don't wander so far of anymore.
What is a house:
Here some samples of houses.
Hints for houses:
-Be carefull when designing the "roof" of the house. If left and right from a door, the roof is equal long (like 5 blocks left and 5 right) it is not a house anymore. Any solid (not transparent) counts.
-spread them more out in your village area! This raises the general population grows.
-You can place easily a lot of doors on the existing house walls outside to raise fast the villager population
-double doors or doors which are connected to other doors are all seperated doors(houses)
For small villages here some special hints because villager can easily wander off:
-FENCE in or wall in the villagers or better the whole village
-Build fast more houses to increase the village size
-create more spaces which villagers can reach and travel back and forth(roofs, cellar, even save caves)
-secure at last 2 of the villages by confining them somewhere.
Different village sizes and population grows ratio:
-Small village under 40 tiles wide or long (Villager tend to wander off and it becomes easy a ghost town if you don't help them) (population is around 1 house = 0.35 Villager)
-Normal villages around 60 tiles wide or long (Population is around 2 houses = 1 Villager)
-Big village around 60-100 tiles wide or long (Population is around 3 houses = 2 Villager or infinite)
-HUGE village around 100+ tiles wide or long (Population growth is easily infinite)
Spreading villager over your villager with "hotspots"! (to prevent clustering a bit on one spot):
Because the social behaviour let them go to where others are!
You still can't get golems or villager to breed? Post a screen of your village, and say how many houses you have and population. I will look on it and help. Please use spoiler tags for your picture.
You can do them with [.spoiler]picture [./spoiler] without the dot.
If your Village population gets too high
and you don't want to kill them off with tnt because you like your village, here some funny solutions! Because sometimes hundreds of villager are just to many! Lot of people complain about lags because of them.
Suicide bungee jump tower and Crematory 2.0 solution:
Pillow suffication station 1.0 solution for daytime suicide:
Villager Death Parkour 3.0 solution for daytime and nightime use, villager killing each other:
Golems spawning requirement:
-minimum 16 villager (generated or natural doesn't matter) for a chance to spawn one, the next on 32,48 etc.
-They sometimes need just a lot of time to spawn, this means maybe some mc days.
-Houses: At least 21 "houses"(doors that count as houses) must be in the village.
-They spawn randomly in a 16x6x16 area around the center of the village (center is the average coordinate of all houses, not villagers)
-A higher golem limit doesn't effect the spawn rate. The spawnrate is a fix value regardless on how high your limit is.
Your village died out or you created your own village, what now?
-Build it up a bit more if it's died out and use the above hints to secure a living area for the future villager
Now you have 2 options.
-Get 2 villager, or more from a other village and repopulate your village
-or use a mod and spawn 2
-Here a thread how to transport villager to your own village, they doesn't care if the village they live in is a natural or a generated by you
Minecraft wiki for villager and golem (beware it's not all 100% right there and not everything is stated there too).
Useful Mods related to Villager, Villages, houses and Golems:
-[SSP] Villager Info by trunkz
gives various information about the village you are currently in, like villager, houses, golem count, the size of a village and the center of a village. It's ideal for checking if you fullfill conditions for breeding or golem spawning.
Thanks trunkz, KyoShinda for getting the stuff right.