General terms:
* Collection
* Set
* Library
* Archive
* Corpus (a collection of written or spoken material)
Specific terms based on content:
* Series: A group of books with a shared theme or characters (e.g., Harry Potter series)
* Anthology: A collection of stories, poems, or essays by different authors
* Omnibus: A single volume containing several complete books
* Canon: The body of works by a particular author, or a group of works considered to be important or influential
Other terms:
* Shelf (when referring to a physical collection)
* Bibliography: A list of works by an author or on a particular subject
* Catalog: A list of items in a collection
The best term to use will depend on the specific context.