You can export references from the library website to your EndNote Online Library using the EndNote button. With most other websites and databases you will need to use the export RIS option.
You can install EndNote Capture to capture online references from webpages. You must first sign up at http://myendnoteweb.com
To use it, browse to a page you like and click the Capture Reference button in the Bookmarks bar. The Capture Reference window will open. Follow the instructions in the window.