Over the holidays, I found out that you can actually 'build' your library online with google. First, you must have a free account to do this. After getting your account, go to the book part of google at books.google.com. Establish your library by going to 'your library' and creating an account with a 'nick name.' Find a book that you already have in your possession, click the link add to library. It will add all the information about that book into your library including the cover.
I recommend begin with the author you already know you have. Place their name in the search and all that author's books will come up. You can then just click down each one you possess.
After you begin doing this, go to your library and view your books. You can view them either by cover or by list view. Either way, you will still be able to see the covers.
I spent a whole evening doing this. I had a great time doing it. There were some I didn't even know. I later found out that I have almost 300 books. Presently, most of them are boxed up because of us living in an apartment.
Click away. You will have a great time.