There is no specific mining area; you just mine wherever you want to.
There are no helmets made specifically for Mining, but normal Helmets do exist in Minecraft.
In the full version of Minecraft, obsidain is usually found in the deep part of caves. Since there are no cave systems in minecraft pe, it's really hard to find it. You just have to keep on mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining and mining until you luckily find obsidian.
You don't make diamonds (unless, probably, if you have Tekkit), you find them. I suggest mining around lava pools or mining 7-12 blocks above bedrock, as a whole lot of other goodies and stuff is around that area.
Ace of Spades is a combat focused game based on the Minecraft blocky world. Dig-N-Rig features the mining and building aspects of Minecraft. Minecraft is partly based on Infiniminer, a block-world mining game.
The name "Minecraft" means "The art of mining"
By mining stone.
I find diamonds by mining at bedrock level.
Herobrine.
Minecraft doesn't stand for anything. It is Mine, which means Your world and mining, and Craft, which means crafting.
It is found in caves and can be requires when mining with a Pickaxe.
mining at about level 14
You can find them by mining in extreme hills biomes.