consider using space above door and shelves instead of "built-ins" or bookcases, for max storage "wall of books" feel.
One of our favorite small space secrets — one of those little things that takes a space from good to great — is wall mounted shelving
When you're living in a small space, every detail counts
We've compiled a short list of some of the handiest and most versatile IKEA products for small space living.
Micro Makeover: 5 Bookshelf Revamps That Will Make You Want to Read (MyDomaine)
The Container Store's Elfa system (as seen in this room from Hemnet), provides a lot of options - High, Medium, & Low: The Best Sources for Wall Mounted Shelving — Apartment Therapy's Annual Guide