Wood is used for many things and is one of the first crafting materials you're gonna need for many other things. There are many types of wood, or wooden objects. Here's a list of most/all of them:
Tree trunk, Bush stump, Large tree trunk, Haft, Rod, Stalk, wooden segment, wooden hull, plank, and maybe more.
Here's a list of things you can craft with Wood:
Haft = 1 bush stump or 1 rod or 1 stalk
Rod = 2 haft or 1 tree trunk
Wooden segment = 2 tree trunk or 1 large tree trunk or 2 plank
Wooden hull = 2 tree trunk or 1 large tree trunk or 2 planks
Tree trunk = 1 large tree trunk
Planks = 'place in lumber mill'
There maybe more "wooden" items that aren't listed here. If there are any missing, please comment or edit the page.
Here's a list of wooden buildings/vehicles:
Wood Hut = 4 wooden segments and 2 foliage thatches
Small Wood Hut = 2 wooden segments and foliage thatch
Wooden Granary = 2 wooden segments
Palisade wall = 2 wooden segments
Palisade/wooden gate = 2-3 wooden segments
Palisade tower = 2-3 wooden segments
Mill = 3 wooden segments
Lumber mill = 4 wooden segments
Cart = 2 wooden hulls
Siege tower = 6 wooden hulls
Fence = 2 planks
Ladder = 2 planks
Table = 3-4 planks
End table = 1-3 planks
There are obviously many more buildings/vehicles that aren't listed. Please edit and add the recipes if you know them.