The video is a good guide to show you several benefits you get from using Zotero. You can save citations into your library using the address bar icons (Zotero Connector), add item by ISBN, DOI, or PubMed Id (button in tool bar), create new item from current page (button in tool bar), manually add items, drag and drop pdf or by using database citation export tool.
Address Bar Icons: The easiest way to get items into your Zotero library is by using the address bar icons (Zotero Connector). Zotero's strength is that it recognizes when you are looking at information for a book, article, or other source in your web browser and inserts a "save reference" button right into the address bar. Depending on what type of reference you are looking at, the address bar icon will be a book, document, newspaper, etc. To save the citation simply click the icon. If you are looking at a list of references, you may see a folder icon. This icon allows you to select multiple items from the list to save.
Article Icon in a Database
Folder Icon in Google Scholar
If you have an DOI, PubMed ID, or ISBN number it is easy to add the item to Zotero. Simply click on the magic wand icon from the Zotero toolbar and enter the number into the pop up window that appears at the top of your browser.
In some cases, such as a reference in print, you may need to manually add a citation to your Zotero library. To add a citation manually, simply click on the plus button and select the type of citation you would like to add. A blank item will be added to the middle column. Click on the item to view the information on the item. Click to enter information in the fields for title, author, publication information etc.
It is easy to add a PDF to your library, simply open Zotero and drag and drop the PDF into the collection you would like to add it to. If the PDF has been created with Optical Character Recognition, Zotero can retrieve the metadata for the PDF. Either right-click (PC) or control-click (Mac) and select Retrieve Metadata for PDF from the drop down menu. (Note: if the file is downloaded from a library database or it is well indexed, zotero will retreive the metadata and create a record automatically)