Daughter wants to put 3 to 4 'peninsulas' into the attic/apartment to break up the 50 foot length. These would be built perpendicular to the wall, stick out 3.5 feet and be about 28-30 inches high.
I would like to build a box out of 2x10 lumber and screw it to the floor joists and adjacent wall for stability. The final look should be white melamine or equivalent. Top will get a 2x12x1/2" board. Everything will need to end up white.

What's the easiest way to go from a "2x10" box to a decent looking bookcase.. A shelf midway up from the bottom would also be nice. The back can be 1/4" melamine panel. What's next? False horizontal member to get the books 3-5 inches off the floor? Build a face frame? Line all the 2-by material with 1/4" melamine?
Help !!

Thanks, Ivan Vegvary