Ores are collected for crafting, decorating and for other purposes, such as for tools and armour. Ore can also be combined to create a block of the material's type.
Coal - Used for furnaces, sometimes found on cliffs but also underground
Iron - Used for weaponry, armoury, decorating etc. Found underground.
Lapis Lazuli - Only used basically for dying wool. Found underground.
oro - Same uses as Iron, and when crafted into a weapon, tool o armour, easiest to enchant. Found underground.
Redstone - Used for advanced stuff e.g. piston door, and crafting pistons etc. Found underground.
Diamond - Same uses as Iron, best ore used for weapons, tools etc. Found underground.
esmeralda - Rarest of ores in the Overworld, only used for decorating, crafting etc. Found underground.
Nether Quartz - Only found in the Nether, used for decorating, crafting etc.
Maybe this is enough information about ores!