Resources are split into 2 main groups, Materials and Food.

Here is a full description of the materials group:

Gold Used as a basic currency for buying and selling goods. It is also used in the training of soldiers, Wizards and Scientists. Another use for gold is in the payment of repairs to your buildings. It is good to keep a supply of gold for emergencies.

Wood and Stone Two of the most basic building materials. The Stone can be mined or recovered from around the landscape. You will need a Foresters Hut to collect wood from the trees.

Coal, Steel and Ore The Coal is used in the refinery to create Gold and Steel. It is also used in the process of making armour. The Ore is broken down in the refinery to form Gold and Steel. The steel is used to create Armour and sometimes as a building material.

Water A very important resource. Used for refreshing your people in it's basic form and used in the Brewery to create Wine. The water is also used by some buildings as part of production.

Oil Used in the Laboratory as a part of experiments and it is also used by the Peasants to set fire to buildings. Without this element you will not be able to develop new technologies and the torch building command will not be available.

Armour Armour is sometimes used in the Building process to create strong forts. It is also used in the process of training Soldiers.

Magic Used by the Wizards to create buildings, trees and other Wizard type activities. Without Magic the world of Foundation will be out of your control and you will become defenceless to attacks such as fire.

Ideas The Idea element is really just a Blue Print containing new ideas developed by the scientists. As soon as the idea arrives in a Storage building it can be used to upgrade your technology in the form of new buildings, character commands or upgrades.

Cross The Cross represents the Soul of a dead person. When a member of your population dies the Cross will appear as the last remains. These Crosses can be recycled in the Crematorium to produce Magic.

And the foods group...

Bread, Meat, Wheat, Wine, Vegetables, Fruit & Fish

All foods work in the same way but certain activities require different groups of food. The soldiers working in the forts will enjoy eating Bread and Wine while the scientists like to eat Fish and Vegetables while they are working. The Wine can be used to increase morale among your population but it doesn't have a good affect on health.