Each village has an NPC to access that village's warehouse. Your warehouse is shared across a single family, and has a transport function to move goods between Warehouses.
Any item except a bound item can be deposited into the Warehouse, and the Warehouse has no weight limit.
Silver is also deposited into the Warehouse, and can be used to purchase from vendors and the Auction House from the warehouse.
Warehouse slots can be expanded by purchasing Warehouse storage housing units and/or Patron status.
Increasing Warehouse Slots
Each village offers a basic 8-slot Warehouse.
You can increase this by another 16 by purchasing Patron.
You can also increase the amount by purchasing housing units as Warehouse Storage units.
You can Transport items between Warehousing through the Warehouse Manager or World Map. The price to Transport items increases with distance, and the cost is tripled if you transport between nodes which aren't connected.
You can keep track of your progress by looking for a gift icon on your world map, and it will show you exactly where your items are during the transport process.