Provinces and Buildings
Each nation starts with a certain number of provinces, of which some produce resources while other only produce Manpower and Money. Manpower and Money are produced globally (meaning everywhere). The provinces also differ in the number of Victory Points they grant you, some provinces don't give any at all.
If you click a province you are able to see the daily production on the far left of the popup (shows a resource, money, and manpower indicated by a green helmet). Clicking the 'i' next to Productivity per day will show you the production of resources, if there is a non core penalty, daily consumption (if it's your province) and population.
Other valuable information you can see is when you click the 'i' next to Morale. It will show morale percentage, morare trend (the rate morale increases in the province), army strength (if theres an army stationed), and morale influences (factors that affect morale development, such as distance from capitol).
Having low Morale on a province might lead to a revolt - the province declares itself as part of another country.
Daily consumption is quite important - failing to fill it leads to a drop of morale. Running out of food/oil can start a decline in morale, as will declaring war with multiple countries.
To raise Morale in a province you might either use Gold or fill their daily consumption and the morale will raise slowly at daychange. Also, building fortifications and placing your capitol close to provinces can help.
Victory Points, Province type and terrain
In the upper right of the province menu you can see information about the province type. Non-core provinces are occupied and have a -75% production penalty. They have a striped backround. You can also see the flag to the left of "Core Province" or hover around it to see who owned that core province.
The star next to the province type indicates the number of Victory Points. This is what you need to reach the required VP to win the game. The amount of VP varies depending on the province and amount it has been upgraded. At the end of a game, all remaining active players earn gold from the VP.
The image on the far right (the trees in this picture) shows, which terrain the province is. Terrain is a key factor that will affect the outcome of many battles.
Each type of terrain has different features:
Plains - Motorized units are faster on plains. Tanks can use their maneuverability to inflict more damage to their opponents. Motorized armoured units gain a +50% strength bonus on plains as well.
Hills - Varied terrain which both - infantry and mechanized units can use to their advantage. Militia gain a +75% strength bonus.
Mountains - Rough Mountains reduce the movement speed and combat strength of all units. Only commando units have special training to excel in this terrain (a +100% strength bonus). Motorized/armoured units suffer a -25% strength penalty.
Urban - Tanks are slow and easy targets for infantry units in urban combat. All motorized armoured units suffer a -50% strength penalty. Tanks in addition to the strengh penalty, have half of their max HP (Health Points).
Construction, Production, Spies
While the "Construction" button opens the menu to construct buildings, "Production" on the other hand is where you can create units. The "Spies" function shows you the number of active spies and lets you recruit or dismiss spies. In your own nation, the last function on the far right is the "Rally Point" (a High Command feature) which can be dragged to set a point for your troops to gather. In a foreign nation you will see the ruler instead, as well as their relation to you (e.g. Peace or War).