Instructables

Step 6: Build Your Bookcase...

So you build your book shelves/case... 

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.