Here's how I organized my books:
1. I sorted by theme, genre, or author. (used a variety)
2. I took pictures of groups of like books, according to the before mentioned groups.
3. I placed cropped pictures in a Dropbox file folder (I pay for the Pro version which is 1TB-plenty
4. I created a QR code for each folder. I used qrstuff.com.
5. I numbered my boxes and put the appropriate codes and books together (notice in the picture the hanging numbers-qr codes are behind them).
6. Next project: I will number my books so that students can help me keep the library organized.
*I can't wait to need a book and go right to it. I can even do a search in my Drobox Library folder
for particular books and find its sub-folder or box that it is in.