Where is library information held and can you change the icons assigned to a book

I'm using ADE 2.0.67532 (Adobe Digital Editions) and have a couple of questions:

1-In the libraries there are icons associated with the specific books that look like book covers. Is there a way to change these icons (i.e. can I create my own picture and attach it to the book)? It seems to create its own icons when you add a book.

2-This brings up another question, *where* is the information for ADE stored (where is it getting these icons from and where is the bookshelf set-up stored, in another directory somewhere. I don't see anything in the ADE directory itself)?