I keep getting a "SECURITY CERTIFICATE" warning.

These messages refer to potential issues with the Library's security certificate.  You can safely accept the risks and continue onto the Library website.  Here's how to accept risks in each of the major browsers:

Chrome:  Look for the little shield icon next to the URL bar at the top right. Click on the shield and accept the risks.

Internet Explorer: Click "Continue to this website."  Follow the prompts to accept the risks.

Firefox: Click on the icon at the beginning of the URL in the address bar.  There should be a "This connection is untrusted" warning. Click "I understand the risks" and/or "Add an exception" for the page you are trying to enter.  

Safari: Click on  "This connection is untrusted. Safari cannot verify the identity of this website"  Click on "Show Certificate." Then accept the risks.