You will find e-books mixed in with print books in the library catalog. If you would like to search for e-books only, select "Online Resources" in the search bar, or use the filters at the left to limit the results. E-books will be listed as Books but will say "Available Online".
Once you have found an e-book, click on the link labeled "Available Online". That will open further details about the book. Look for "View Online" and click on the link under "Full Text Availability".