The green plus button allows you to manually create new references if you cannot find the reference online.
However, it is generally faster if you use the Zotero Connector to clip citations from the web. Read on below under "Saving Citations" for more information on using this.
Another time-saver is if you already have full-text PDFs of academic articles or book chapters saved elsewhere on your computer, Zotero will attempt to backsearch the web for their citation information (metadata) when you place them in your library.
You can add them to your library by dragging and dropping single items from your files, or, you can select "store copy of file" under the green plus button's menu in Zotero. Zotero should automatically attempt to make a citation to go along with your PDF once it is added, but if it does not, you can right click the PDF and select "Retrieve Metadata for PDF."
The video below provides a broad overview for how to create and save citations in Zotero. All information in this tutorial also applies to IU Libraries' resources.
Zotero allows you to save references from most library catalogs (including IU's), databases, and some regular web pages with one click. If Zotero detects that you're looking at a book or article, you'll see a book or page icon in your browser's address bar. Click the icon and Zotero will save the citation.
If you're on a page of search results with many items, you'll see a folder icon instead. Click this to get a list of the items on the page, and check off the ones you want to save.
Have the book in front of you and want to add it to your Zotero library without having to search for a citation? If you have a book's ISBN or an online article's DOI or PMID number, click the "Add Item by Identifier" button (appears as a magic wand) within Zotero 7. Type in the book or article's number, and Zotero will automatically download its information and save it to your library.