This "Help and Information" section is designed for web designers who build and/or maintain WordPress websites. Because of that, if you are not familiar with phrases like "CSS class" or "element tag," the help and information given here will not necessarily make sense to you.
The CSS Diagrams offer maps between CSS and HTML. There are examples at the bottom of the screen to help guide you in style sheet creation and modification of the 5 customizable notification types: Receipts, Confirmation, Cancellation, Welcome/Account, and Notice of Pending Charge.
The Welcome/Account tab explains how the CAM, WordPress, and your Welcome email all work together.
The Notification Samples tab allows you to see what your current notifications look like.
The Dynamic Content Reference is exactly that. It is a section that lists most of the dynamic tags you can use in creating or modifying your customizable notifications. For your convenience, there is a downloadable PDF of this list.