Google Analytics and Tag Manager Integration HUB
You will find a general presentation of the Google Tag Manager integration, in SecuTix - Google Tag Manager & Google Analytics.
Then, if you want more information about the technical side of it, head to:
Technical presentation of the SecuTix Datalayer, and
And you will find some specific use cases in:
Cart and user info tracking - extend the enhanced e-commerce to the next level
Google Analytics improved data layer for products and checkout
Improved Google Analytics Data layer for calculated season ticket sales
About SEO, look at these: