To write your content in Author-it you will need to assemble existing objects and create new objects. Start by building your document's structure.
First, create a Book object, which will represent your document and will act as a container for all the other objects that make up the document. You'll see these objects in the book's Content tab. You can now add a Title Page object for your printed output, and a Table of Contents object.
Create a Topic object for every heading in your contents outline. Enter the topic's description and apply a template (Chapter, Normal, and Procedure are the most common), but it's good not to add much text at this stage.
As you add topic objects, make sure you move them into the correct hierarchy. You may add a Glossary object to your document, and hopefully an Index object.