Physical books live on shelves and move in packages that are neatly labelled with all kinds of useful information. In the virtual places that ebooks live, those neat labels are their metadata: lists of information about a book. And in the best ebooks, even their parts (chapters, subsections, even paragraphs) have metadata labels. Without them, ebooks are as useful as boxes of books in your warehouse with inaccurate or absent packaging labels.
Without good metadata, it’s impossible to manage or search more than a few books at a time. At its most basic, metadata includes an identifier like an ISBN, and a title and author name. At its most impressive, metadata labels (or tags) every little piece of a book with potentially useful information. (See this piece by provocative but insightful blogger Mike Cane for an idea of how detailed metadata could be.)
Any good DAMS will include good systems for managing metadata. And if you don’t use a DAMS, you have to have clear policies in-house about what and how metadata is stored in your ebooks. This is partly an administrative issue, and partly a technical one, since there are different systems for storing metadata, and you may have to choose between them. Again, get the IT people out of the basement!