There are a number of ways to get books, articles, web pages, video clips, blog posts, and other kinds of information you may want to save into Zotero. Here is a list of ways to do this:

1. Browser extension: When you visit the library catalog, databases, journal websites, and many other Zotero enabled sites, you can click the icon that appears in the Zotero browser extension to grab the citation information for you. The browser extension will also grab metadata from webpages and save archived copies of the webpage. 
2. Retrieve Metadata for PDFs: Zotero can identify the metadata associated with most article PDFs you have saved on your computer.
3. Look-up Items by Unique Identifier. If you have the DOI, ISBN, or PubMed ID of an article or book Zotero can look up the citation information. 
4. Manually Adding Items: Items can be manually added by clicking the New Item button in the Zotero toolbar, then selecting the appropriate item type.

Zotero allows you to save references from most library catalogs and databases, and even some regular websites and online videos. If Zotero detects that you're looking at a book or an article in a catalog, database, or website, you will see a book or page icon appear beside the address bar of your browser. Simply click this icon and Zotero will automatically save the citation. If you use Zotero Standalone (the desktop application rather than the web version) you will need to make sure you have the program open before you start saving citations. Zotero will save to the folder you have open, so make sure you have the correct folder open before you start saving.

On a page of search results you will notice a folder icon in place of the book or page icon. If you wish to save multiple items in a search you can click the folder icon and then select the books/articles of interest in the pop-up and click "OK". If you are in a database with multiple pages of results, clicking on the folder icon will only show you that page of results. 

Zotero includes a feature that allows you to retrieve the citation information, or metadata, from many article PDFs. Simply drag and drop your PDF into the middle pane of Zotero. If Zotero can detect the citation information, or metadata, it will automatically create an item in your Zotero library for the article.

The ability to retrieve PDF metadata will not work with every article PDF. If you're trying to retrieve PDF metadata in Zotero and it does not work, you can manually add the items.

Manually inputting citations is a good option if you have a PDF that you cannot retrieve the metadata from, or if you want to add a citation from a print source. To manually add citations, click the green plus sign above the middle column and select your document type. Once you have selected the document type, fill in the title, author, and fields related to publication/publisher information.