Crafting is not a skill-based system; instead, it is very much like the system of advancing classes. There are multiple tiers. You begin digging, you explore and you find things, and those things give you progression and advancement that can be spent on your crafter. Exploring through the world is, in itself, an element of crafting. Crafting will not be about making the same thing over and over again repeatedly to advance your skill. An individual character can harvest everything in the world and can progress in multiple crafting classes.
Weapons are made out of multiple parts, and each character class or multiclass build will have different requirements and different ways that you can augment and fine tune the weapon. One can tell what an equipment item’s properties are just by looking at it and recognizing the material out of which it is made. You can make your weapons and abilities stronger by finding different things, and you can mix and match those different things on your weapons to give them elemental or other kinds of powers. If you want to make a weapon that does electrical damage, or a weapon that is really strong against undead, you need to find the right material to make it out of, and that could be any of the materials you find in the world.
If you’re an MMO player, you might expect copper to be a newbie metal, found right outside the starting city and eventually it wouldn't be needed anymore. Because of the way our game works, copper is always useful, because copper has specific qualities. Iron is always useful. Mithril is always useful. All of these things are always useful to you, depending on what you want to make.
There are no harvesting nodes. The world itself is made of resources. Things are where you expect them to be, and you’ll find copper where you think copper might be. You must consider where different resources might be found, like on the mountains or underwater. Dirt can be found pretty much anywhere. Obsidian may be found in or near volcanoes, subjecting you to the dangers of lava, and there are itemization options that will let you circumvent such danger. Mahogany might be harvested in the forest. These resources can be sought after naturally using what you know from outside the game. In other cases, such as mining for mithril, game specific knowledge may be helpful. For instance, mithril may be found deep within specific mountains.
The world consists of tiers, and that applies to harvesting as well. You'll be surface mining and harvesting deep beneath the earth. When you harvest, it destroys the world for a temporary amount of time (5 minutes). You harvest, it destroys things, then the world heals and some of the resources that you've harvested are moved. Depending on its material, each voxel has different sounds, mass, and physical strengths. A mithril pick literally opens up more world than an iron pick, and you can dig deeper and through tougher materials. While granite can't be beaten through with an iron pick, it will say right on the mithril pick that it can mine that certain type of stone. A mithril pick also allows you to more easily harvest lower tiered things. Through the use of such harvesting tools, there will be basic and more specialized harvesting.