I Love Picture Books!!!!! My collection is out of control.
They are organized by AR level, but I needed a method for indexing, so I made an Excel document that works wonderfully well. Plus, it's very easy to update.
The advantage to using Excel is that it allows you to sort by column. I made columns for AR level, Book Title, and Author. I also added columns to signify if I had a CD of the book, multiple copies of the book, and if I had a "Book Kit" (set of supplemental materials to teach the concepts in that particular book). I then printed a sort by title and a sort by author, and put them in a folder that stays on the top of the bookcase. This system allows me (or others) to quickly find any book in my library. As I buy new books, I write them in and only update on the computer after I have several new books to add.
I love to have audio recordings of my picture books. Ever wonder how to store those CDs?
Keeping the CD with the book used to be a problem for me until I purchased some CD sleeves and some double sided tape: