The Chicago School libraries are providing you with access to thousands of online books through ebrary. The books cover most of the academic disciplines so you can go beyond Psychology books if you're interested.
The easiest way to enter ebrary is through the library catalog - a link on the library's homepage. Search the catalog by subject, title or author and a list of all the books in the library (both hard copies and online) meeting your criteria will appear. The books on ebrary will show as [electronic resource]. Just click on the book's title, scroll down to the bottom and click on "An electronic book accessible through the World Wide Web; click to view" You will be asked to sign in, and you will then be taken directly to the book in ebrary.