Hi Sarah,
There is an error with ebooks that occurs when you are logged into the catalog in advance and then try to access the ebook. You will get a log in screen that looks like this:
This log in screen does not work. If you see this screen you need to log out of the catalog, completely close down your browser and then reopen it and search for the book again. You should get this log in screen:
This log in screen should work with your library account immediately. If you haven't set up a library account. Click the set/reset password link to set it up. At one point it will ask for your username, but it wants your NU ID number. This account will take effect immediately.
Let me know if you have more questions.
Katie