The functionality of Repeats, Flow Directions and Special Endings are covered in detail in the NoteWorthy Composer Help File, examples are shown in the User's Guide and the 4 sample song files repeatx.nwc (where x=1-4) in NWC allow you to follow the flow by playing back the files. Go to File: Info for each file for an explanation of what is being illustrated. All of these resources should provide a good understanding of how these features work.
An additional tip when working on the flow of a song is to break the song into blocks. These blocks are individual sections that may or may not be played more than once, but they can be separated. Then give each block a name, like A, B, C, etc. Then write out the flow of the song, using the block names. For example, your song may flow ABACDAC. From that, figure out how to implement Repeats, Flow Directions and Special Endings in your song. This will help you see at a higher level without all the measures of notes clouding your view.