If you want a cataloguing app for Linux that'll handle books, DVDs, CDs & more then have a look at
Tellico.
Currently using it to catalogue my music collection. Point it at a music folder & it will automatically import id3 tag data (recursively), point it at a CD & it will download details from a CDDB source. It can also import or link to cover images, print reports etc...
A brilliant program, plus the author is approachable for help or suggestions for features