Commodities are the main building blocks of nations, and all Basic Resources will end up becoming commodities. There are three main types of getting commodities: using a factory to get it from scratch (money > farm > food), use a discover-able resource to put into a factory to get a commodity out (iron > iron smelter > metal) or buying it directly off the market. All three of these have their advantages and disadvantages, and a combination of all of these would be optimal, as it depends on the resource, what should you do.
Money is the most useful commodity in all of Nations. It is used to build & collect resources from factories, buy items, buy other commodities on the market and recruit units for your military. It is also the easiest commodity to obtain. There are two different factories that you can use to get extra money but ultimately they're a waste of resources and you can get at least 10x the money you get from those factories in Tax Interests.
Gold Mine: 1 Gold (Tier 4 Geologist) + a bit of power for 35 Money
Silver Mine: 1 Silver (Tier 3 Geologist) + a bit of power for 20 Money.
Food is required for the upkeep of you population, the growth of your population, government and military. You can initially collect it from Farms. However, buying it off the market is costs nearly half what it does making it from Farms. Later, there are other factories, such as the Supergrass Producer, that not only produce food but also other resources at the same time (for the Supergrass Producer, it's Food and Consumer Goods).
In the early game, it is recommended (not necessarily by others, but by me...) to have enough food as possible in order to maximize 'auto' growth. If you do not want to have a stockpile at all times, you can go to the customize menu and 'set growth' to a manual amount, set by the limits shown. (look right for how...)
Power is another initial resource, needed for urban usage, the allowance of growth (without it, you cannot grow, even with the land and the food requirements) and to produce resources. There are five different factories in which you can produce Power. Nuclear Power Plants produce the most power, but require Uranium to power them (1 Uranium + a bit of money > 80 Power). Coal Power Plants produce money but require Coal (a resource found using Tier 1 Geologists; 1 Coal + a bit of money > 24 Power). Hydro Dams/Plants are quite efficient and are easy to build (9 Money > 16 Power) but they use up 5km2 lakes, which for most continents is a bit irritating as they can't get lakes and rivers from Expanding Borders. For those who don't have lakes or rivers, you can use 1km2 Cleared Land to build a Windmill (6 Money > 6 Power). These aren't as efficient but can be built quickly and cheaply (assuming you haven't reached the tier limit. If building factories fails, then you can just buy Power cheaply off the market (1 Money > 1 Power).
Building Materials are, well, building materials. They are the 'most basic' building material and can be used to craft, build factories and buildings and recruit units as well as expanding borders. You can build factories to make building materials, but it is not that efficient. It is cheaper to buy building materials off the market, as it effectively cost 5 money for one building material.
Consumer goods are used to keep happiness high and expanding borders. There are many ways to get these, such as building on top of trees, such as rubber, coffee, coca, grapevine, and many others. Without consumer goods, you lose 4 happiness (assuming you are over 100k population). The most efficient way to get consumer goods is a brewery that gets one consumer good for 2.4 coins (assuming power is 1) or Tobacco Plantation with efficiency increases. However the resources required are rare, and there are other alternatives.
Metal is used for colonization, recruiting units and building/upgrading building/factories. It is relatively expensive to buy at large quantities: 7.5k metal is needed to be used to build an airfield, and it would cost 547.5k (assuming it costs 73, what is the average at the time of writing). There is a large array of making metal, such as from bauxite, iron, stone- silver, copper, platinum. Another advantage of using these is not needing to use metal to upgrading efficiency (except stone-silver, as it outputs other things), which makes it cheaper to upgrade, what is a good thing.
Ammunition is used in the army exclusively and is first used in M1A1 (if they 'go on sale', then desert fox body and navy seals are first). They are usually used in small amounts (the highest is 5/hour on the Gearhound warhead), but it is usually hard to have a consistent supply of it. If someone runs out of ammo, there units that require it will drop to 20% and will be hard to go into battle and could be annoying in a war.
Fuel is used in armored units, such as tanks and aircraft, as well as for colonists. It is a similar situation to ammo where the first units to use it is M1A1s (or T72s) and the highest consumption would be the Gearhound Warhead. And if one runs out of fuel, then most of their military will be redundant
Uranium is used in power production and level 5 units as well as crafting. It isn't needed til late in the game
WhZ is currently available in game, but is currently in a bugged state. Stian needs to fix it.