These shelves only take two and a half sheets of plywood (oak) to build, but the shelves are deep enough to display books, collectables, etc. The shelves, including the one behind the doors, are adjustable. Tongue and groove joints used throughout this project.
Size: 8in tall x 30in wide x 16in deep.

VERY comprehensive plans! Includes detailed step-by-step booklet (lot's of drawings, 3D and exploded views), cutting diagram, shop tested tips & tricks, professionally drawn blueprints, and shopping list (for wood, hardware & tools needed). Moderate to advanced woodworking skills required.
These are some of the most detailed plans I have seen! Unfortunately, quantities are limited.

BONUS: Includes plan for a Flush Trim Router Jig !

These plans are published by Woodsmith Magazine