Literary all over the map you can usually find cave entrances above ground but there is a vast amount of caves underground.
If you go near them they blow up. You can kill them with a sword. They spawn only at night or in caves; Somewhere dark
Endermen spawn in caves or at night like other mobs. They are also the natural inhabitants of The End.
A spider in minecraft is a mob, It has 16 hearts meaning it is the hostile mob with the least health. There are 2x2 blocks wide and one block tall. It is only hostile at night except for when in caves.
By mining down, adventuring in caves, and if you are lucky iron can be found above ground in stoney areas or pools.
Coal is very common. Caves are a good source of coal, but if you are mining, coal is most common at y=48.
no
No
You find them
No
no
Yes
yes it even has casmes
yes. (except super-flat worlds)
caves and cliffs update
mine shafts.
Thebogsofgob
It is found in caves and can be requires when mining with a Pickaxe.