Miners will be crafted with iron, diamond, gold or stone, it will be placed in all of the corners, then put a pic-axe in the middle then you will get a spawner block then place the block (duh) and after they spawn you press left click (or whatever button it is to interact with things) on the miner, 2 inventories will pop up, one is yours the other is the miners, you then give him a pic-axe and food (other wise he will starve, in other words you have to give him your materials) and you can select which ore you want him to mine, his pic will eventully break (just like normal) and mobs will attack him a But he will not attack them (he's going to die pretty fast and if he dies he will drop what he had, just like normal) and after he collects all of the blocks in that area of what ever you told him to get he will bring it back. So basically, you tell them what to get, you give him materials, he brings it back.
Miner