The resource buildings are the backbone of your village. You can buy and upgrade defensive buildings with gold. You can buy the resource buildings, army buildings and spells with elixir. Dark elixir is used to buy and upgrade dark elixir troops, heroes and dark elixir spells.
You can boost the mines 24 hours for 10 gems, giving you double times the amount of resources. It is recommended to empty your collectors regularly, if you get attacked the attacker can steal up to 50% of the amount in the collectors. The amount that can be stolen in the storages is less. Spend the resources at the moment you can afford an upgrade to keep it safe.
Dark elixir is used for dark elixir troops, dark elixir spells and heroes. Heroes are your powerful troops that can’t die. Be sure to upgrade them regularly.