Google Tag Manager (GTM) simplifies managing tracking codes for your website, making it easier to collect data without needing coding skills. To create a GTM account, visit the GTM website, create your account and container, accept the terms, install the code snippets on your site, and verify your installation using preview mode. Remember to organize your tags, test changes, and avoid common mistakes like improper snippet placement. GTM is free to use and effective for tracking various user actions, including e-commerce transactions.