What exactly CAN I do with iBooks

I have lots of books in that other ebook database (Calibre) and in the course of time I exported a handfull to the iBooks library. Unfortunately it seems that it is not possible to edit or supplement metadata like Categories, Authors, Titles. So what use is iBooks for other things than storing ebooks? Is there a way to dig in the info section of the books, just like it is possible with iTunes and your records.

thanks in advance for your help.

Hans