Image links for different seasons:
Almost all forests have wood, and many also have resin or timber. Other common resources include coal, bananas, various berries and mushrooms. There's usually no food to harvest so people have to rely on hunting but at least fuel for cooking is readily available. The outdoors version of a hammock can only be built in a forest since it's presumably attached into trees. Forests are dark green on the map and there are little arcs of darker green on it.