My son's bookshelves are overflowing which is kind of great, but sends us all on a goose chase when he has a specific request since our books aren't organized in any way. If I'm lucky, I can remember the color of the spine and that speeds things up. I love this simple book storage idea for alphabetizing books.
Margaret of Homemade City stenciled this for a school library and notes that the idea would translate nicely to a home book collection. It appears that this library is alphabetizing by author (as most do), but you could also alphabetize by title if that works better for your brain.
Each title doesn't have to be in order (that's pretty unrealistic with young kids), but breaking your books down into smaller alpha groups would definitely reduce the amount of time you spent hunting for specific titles. And having kids learn to find the first letter of the title or author and sort this way is an educational bonus.
• See more: Homemade City
(Image: Homemade City)
Ellen's Thirties Style Small Space
Juan's Garage Turned Modern Guest House
Good Food to Share 
The Big Book of Small, Cool Spaces 
Apartment Therapy Presents 
The Eight-Step Home Cure 
Commercial Flour Sa...
10 Picnic-Ready Salads to Eat Outside
Make-Ahead Lunch Recipe: Chopped Kale, Farro & Chickpea Salad
I wouldn't do the alphabetizing. I guess we sort unofficially on book size and board vs paper, and husband the 'shove anywhere' method - but I second the 'bin' idea. We put library books in a crate once and found we'd stumbled on the best solution from a kid's perspective. More space efficient than front-facing, more accessible than shelves! But shelves still store more than a crate so in our small space, shelves it mostly is. BTW, as others have noted before me, the kids section in French libraries have a lot of kids books stored this way for the smallies, too.