Libraries and Zotero users have produced how-to videos, many of which are linked from the Zotero site, that demonstrate how to use Zotero's many features. Below, see two tutorials produced by Jason Puckett at Georgia State University Library and posted to YouTube.
Installing Zotero and Saving References by Jason Puckett at Georgia State University Library
To see more videos from Georgia State University Library Zotero videos, check out their YouTube Playlist.
Learn Zertero in 30 Minutes by Paul V. Gavin Library at the Illinois Institute of Technology