I found these: http://www.reallygoodstuff.com/product/book+basket+label+set.do and used sticker dots and a permanent marker.
For science books, I used a green dot and drew the outline of a leaf. I marked that bin and every book that goes in it with a dot. Above, you see a collection of "Story Box" books from old curriculum. I used red dots with a square to mark all of these.
I plan to take some time to teach through interactive modeling, a Responsive Classroom core practice http://www.originsonline.org/responsive-classroom/about-approach/core-practices , and really make sure this cataloging system is put to use. I purposely put the dots on the front of each book to make it easy! If you're worried about aesthetics, you can put the sticker around the binding or on the back. I just wanted it to be easy.