Hello, and welcome to the MineGuide! If you haven't read my previous thread about Surviving the first Night, i reccomend reading that before continuing.
Link to Previous Thread: http://www.mmo-champion.com/threads/...e-First-Night)
Well, you've hopefully made shelter, a Furnace, a Stone Pickaxe and Sword, and now you're ready to mine! But before going in, you're going to need to know this before entering. It's a dark and dangerous place in caverns, and it's easy to get lost. But your lucky enough to stumble across this Guide, so you're not going to be lost ever again!
Mobs spawn in dark areas, and as i've said, it's a dark and dangerous place down there, so your obviously going to need weapons. But lets say you die, possibly by a Creeper or Lava. You lose everything! Is there any way you can stop that from happening? OF COURSE! Make a chest (Which i explained how to make in the first guide) and store extra Pickaxes, Swords, Armor, Food, Etc. just in case of death! I suggest making 6 chests, which will equal 3 Large Chests. Make one for Ore and Minerals, such as Extra Iron, Diamonds, Gold, Etc., one for Extra Armor and Weapons, and one for extra blocks and food like Bread and Cobblestone (You won't BELEIVE how much of that you get!). Just like that, you won't have to worry about dying! Unless you lose your house... but what are the chances of THAT happening?
It's going to be dark as Midnight in there, so your going to need torches. How many you bring depends on how long your going to be down there, for a normal excavation, 1 stack of torches should be enough. To not get lost, just use your torches as a pathway, or make a Landmark near a Exit.
Optional, but if you want to have protection when you venture into the unknown and have no iron yet, just get some Leather from Cows. It'll take a while to grind up the Leather, but it'll be worth it. How you make Armor is simple, For a helmet, put three leather in the top row, and the middle row with two leather, but keep the middle space open. For a Chestplate, fill up the entire Crafting Area, but leave the Top-Middle space open. For pants, do the same thing you did for helmet, but put two leather in the bottom row in the same fashion you put the Middle Row as. For shoes, do the same thing you did for pants, but leave the top row empty. Now you are slightly protected from the harmful Creepers and Skeletons!
Some ore can only be mined with a certain Pickaxe. Most ore can be mined with a Iron Pickaxe, though. You should never use a wooden Pickaxe unless just starting out. Stone Pickaxes should only be used for mining Iron, not for major excavations. Never use a Golden Pickaxe, it is completely useless, it mines quickly, but it breaks just as fast. So, having an Iron Pickaxe is the best thing you can have for normal Excavations, until you find Diamonds, that is.
Sooner or later, you will come across a Mossy room with a Mob Spawner. A Certain type of Mob will constantly spawn, until you destroy the Spawner. Destroy the Mob Spawner, and the Mobs will stop spawning, and you can collect your reward from the Chests. Most of the time you will get Ingrediants to food, Saddles, Iron Ingots, and other somewhat useful items. It is possible to break the Spawner, but you cannot pick it up.
If you want, you can bring a Furnace and Crafting table to craft new items with your freshly-gathered materials. This will increase your mining time, by crafting stronger Pickaxes and more Torches. Also, this is actually a MUST, make a house near the mine you found. But before building, make sure the mine is legit, be it a Cavern, Mineshaft, Ravine, or anything that will keep you occupied for long periods of time, you know you'll have to have shelter nearby. Also, make a Crop Farm near your house to have access to Food.
And there you go! You are now prepared to mine correctly! Have fun mining! And good luck finding those diamonds you're trying so hard to mine!