Zotero can save references from most library catalogs (including GIL) and databases, and even some web pages, with one click. (Zotero publishes a list of compatible sites, and many sites not on this list also work.)
If Zotero detects that you're looking at a book or article on a catalog, database, or a site like Amazon.com, LibraryThing or the New York Times, you'll see a book or page icon appear in the address bar of your browser. Click the icon and Zotero will automatically save the citation.
If you're on a page of search results with many items, you'll see a folder icon. Click this to get a list of all the items on the page. Check the ones you want to save.
Other Web Sites
Zotero can't automatically capture citation info from some web pages, but you can still add them to your Zotero library.
Click the Zotero button at the bottom of your browser to access Zotero's controls. Click the page button (to the right of the green plus sign) to save a link to the page. This will save a new "web page" item to your library. You can add information about the author, etc., if you wish.
This will also attach a snapshot of the page to the citation. Taking a snapshot saves a copy of the page to your computer. It includes the page's text and images, so if the page is removed later, or if you're offline, you'll still be able to view your copy.
Click the Zotero button at the bottom of your browser to open your library. At the top left is a folder button with a green plus sign. Click this to create a new "collection."
Create collections to organize your references. Collections are like file folders on your computer, but a reference can be in more than one collection at a time. In other words, a book on the Civil War could be filed in your "Civil War" collection, your "Georgia History" collection and your "19th Century America" collection without having to make three copies of the reference.