From this page of the Valheim game guide, you will learn where to find the extremely valuable resource known as Fine wood.
Fine wood is a type of wood that can be obtained in the game Valheim. Before you can go into the forest and fell the right trees, you need to craft a bronze axe - wooden and stone tools just won't cut it.
Fine wood is mainly obtained by chopping birch and oak trees, which can be found in the Meadows biome. The second way to get this precious material is by looting the shipwrecks located in the Black Forest.
Acquiring Fine wood will immediately unlock access to the new items that can be crafted from this rare resource. It is important to note here the fact that cutting down oak and birch trees will net you Fine wood in addition to regular wood, as well.