The Gold from purchased packs goes to the total Gold balance in the top right corner.
The bonus Gold some of the packs offer usually goes to Items-Resources, in the form of Gold items.
The Gold you receive from Facebook friends who also play World at War goes to the total Gold balance.
The Gold from app review goes also in your Gold balance and the same goes for the referral Gold reward.
The Gold from daily rewards and event rewards goes to Items > My Items > Resources