As you progress through the game you will discover that at one point or another you will need to level up almost evey building type to maximum rank if you want to advance. There is no avoiding this. Your tarvern, quarry and wall must be at their max levels in order to level up your town hall. In addition to that, each town hall level requires a different building, which itself often requires a different building to be leveled up.
In the early stages of the game the only buildings that can be neglected are resource buildings that require only one of each type to be maxed out while any others can remain at level 1.
There are two types of buildings in Rise of Civilizations, economic and military. Below is a list of the different building with a brief description of their function.City Hall
The City Hall is the core of your civilization, without upgrading it you will not be able to progress in the game.Lumber Hill
Produces woodShop Farm
Get stones from hereGoldmine
Mine gold coinsTrading Post
When you have joined an alliance this facility can be used to exchange resources with members.Courier Station
Protects the resources from intrudersHospital
Heal the troops hereCastle
Use Raily featureTavern
Recruit commanders, open chestsBarracks
Train infantry unitsArchery Range
Train cavalry unitsSiege Workshop
Train siege weapons