Videos:
You can find many ZenDesk training videos for free here:
NOTE: separate registration is required on that site. Your current ZenDesk logins will not work.
Plenty of videos regarding Agent workspace, macros, tags, views and much more.
Help articles database:
To access ZenDesk help articles, click on your user profile and select "Agent help center":
You can freely browse huge database of various articles regarding ZenDesk functionality.
How to contact ZenDesk support:
To contact ZenDesk support for a live chat, click on your user profile and select "Help":
From the menu that appears select "Get Help" and start chatting with ZenDesk representative:
Use this freely whenever you have any uncertainties regarding functionalities or to report bugs.