Because the whole piece is based on the room/wall size, I won't be giving you exact measurements. These will vary in your room.
This is also my first "instructable" so please if you have any questions or I've left something out, ask and I'll give you the answer. :)
1 8ft 4x4
2 sheets 4x8 MDF
hinges for door
Step 1: Hyrule Bed
Also you will need to make sure you have the mattress that you want to use for the top and the bottom bunk. You will need the sizes to build the frame.