So I'm watching youtube video's and people have mob spawns around. How do you make them?
Without using 3rd party tools to hack mob spawners in, there is not way to make them. Even then, all they ever spawn is pigs.
Something is supposed to be here....I am not really "Jocas" I am actually JoshuaZY
They either used a map editor to place spawn blocks, or they built around a spawn block that had been randomly generated in the world.
If you use INVedit, which is an inventory editor. You can download this software at the Minecraft Forums. Warning: this block actually is just a block, it doesn't actually spawn stuff. And once you place it, you can't pick it back up.
"Give a man a fire and he's warm for a day. Light a man on fire and he's warm for a lifetime,"
(Except you might kill him that way! Also, in Minecraft, fire can be on fire and can be made into a nice hat... for 30 seconds.)
MCEdit lets you edit the world around you, including adding mob spawners.