Creating a container with Google Tag Manager
Installing a Google Tag Manager plug-in in WordPress
Creating a Variable in Google Tag Manager to store our Universal Analytics tracking code.
Creating a Tag in Google Tag Manager to track PDF Download click events.
Creating a Trigger in Google Tag Manager to fire when a PDF link is clicked (this can easily be modified for other types of files)
Live Preview of the Tag created on the blog website
Reviewing Click Event reporting in Google Analytics
Publishing Your Tags & Versioning
More blogs at http://www.ryann.ca