Go to the Word Processor Plugins page. Choose the most recent version of the plugins if you're installing Zotero for the first time.
Word for Mac/Windows users:
The Zotero Toolbar allows you to insert and edit citations and bibliographies, set your document preferences and remove field codes.
It's easy to create a bibliography from your Zotero library.
Select the references or collections you want to include. Hold the control key (or Command on a Mac) and click to select multiple items. Right-click one of the selected items and choose Create Bibliography.
Choose the bibliographic style you want, select Copy to Clipboard, click OK and paste into your word processor.