Step 6: Build Your Bookcase...
At this point you go by your plans and choose if you want fixed shelves or adjustable. I am wanting some versatility so I am doing adjustable. In order to do this simply you could barrow some ¼ inch peg board from a friend, and use the peg board as a jig. I actually chose to use actual hardware I picked up from Lowe's.
As you can see I did mine out of butcher block because of cost. I am only building a box with a top, bottom and sides out of the butcher block and then putting a back on using some luan or paneling (again to save on cost). There was one shelf that I nailed and screwed in about 12 inches from the bottom (for structural strength and usability).
Painting, sealing or staining... that's all up to you. I would suggest sealing it somehow. I decided to paint mine white to match the other trim and things in my office.