Coal: fuel for all machines. Coal Mines make it.
Iron: metal for buildings and soldiers. Iron Mines make it.
Water: makes steam for engines. Water Wells make it.
Food: feeds workers and soldiers. Mushroom Farms make it.
Gears: made from Iron and Coal in the Gear Factory. Needed for riders, machines and the Great Clock.
Per hour
Every town makes a little Food on its own. Mines, wells and farms make much more. Fast seasons go quicker than Regular seasons.
Storage
Without Storage and a Food Store you can keep 1000 of each resource. When a store is full, the extra is lost. Build and upgrade Storage early.
Keep them safe
Other players can take your resources in an attack. The Hiding Place keeps some of each resource safe.