Following is a list of documentation available in the downloaded Zen Cart ZIP. Click the link to open.
About Zen Cart™
1. Read me first -- Installation
2. Read me first -- Upgrading
3. Configuring PayPal IPN
4. Customizing HTML Email Templates
5. Security - Securing Your Site
6. What's New in v1.2.6
7. Changelog for v1.2.6
8. Summary/Explanation of Product Types