Here is the reality check: remember when you tried to check out books for the beach and found out that book was not available at the library or was only available after waiting three months when you were put on the waiting list. You will encounter the same situation with eBooks at your library.
Once you are at the top of the waiting list for an eBook from the library, how do you download the eBook to your eReader? Download the eBook to your computer via some software you need to download and install. Once the eBook is on your computer, connect your eBook Reader via the sync cable and drag the eBook from your computer to your eBook Reader. Here is a link to directions on getting eBooks from the library to your eBook Reader:
http://beingruth.com/tutorial-library-books-nook-overdrive/
I think the eBook Reader is a great idea, but like anything else, the more you pay for something, the more the item is easier to obtain.