Okay so today I made a golem farm and it simply just isn't working for me http://imgur.com/nUcwYZE (Behind each of the doors is a 4x4 space with 4 villagers.) Anyone have any suggestions to why it isn't working for me?
Looks like the floor might be 1 block too low. I use nim's design almost exclusively now. http://youtu.be/Dev3Ls8papM makes things pretty easy. for the 15% difference in spawn rates you can just make another.
Yes, but it is not easy. You will have more zombie invasions underground, and doors need sunlight level 15 on at least one block next to them, so you will need to dig a column next to each door, all the way to the surface and even remove any trees, leafs, etc at the surface untill F3 shows SL=15 next to the door. To keep surface mobs and players from falling into your square outline trench, put glass blocks at the surface.