To start, I honestly Googled "bookcase chair," scanned through a few images, and then I just started building this Pallet Bookcase Lincoln Chair. It's all my own design since I didn't follow any plans. I can tell you how I started it, but that's about all I can explain.
Pallet Bookcase Lincoln Chair:
I simply went with what I had. On-Hand and what materials were at my disposal. I had Coca-Cola pallets, 7-Up pallets and so on. Typically, I prefer to make the least amount of cuts as possible, so with that in mind I just built the frame from pallet 2" x 4"s to make the vertical legs and to frame out the various box shapes. The basic idea was to avoid getting overwhelmed building one big piece. Instead, I broke it up in my mind as building two bookcases and one chair. As the process went on, I figured it would attach itself. This project used pallet stringers, plywood (both from pallets and scrap), and deck boards to close in areas as needed.