Oracle University has a wealth of free webcasts for Oracle E-Business Suite. If you're looking for an overview of how to manage your customizations when upgrading to EBS 12.2, see:
Migrating and Managing Customizations for Oracle E-Business Suite 12.2 (55 minutes)
Have you created custom schemas, personalized or extended your Oracle E-Business Suite environment? Santiago Bastidas, Senior Principal Product Manager, discusses how to select the best upgrade approach for existing customizations. This session will help you understand the new customization standards required by the Edition-Based Redefinition feature of Oracle Database to be compliant with the Online Patching feature of Oracle E-Business Suite. You’ll learn about customization use cases, tools, and technologies you can use to ensure that all your customizations are preserved during and after the upgrade. You’ll also hear about reports you can run before the upgrade to detect and fix your customizations to make them 12.2-compliant. This material was presented at Oracle OpenWorld 2016.