A journal is, internally, just a list of entry names, stored as a text file in a folder "journals". The idea of a journal is to let a visitor read a series of entries in a given order.
The simplest way to do edit a journal is just to type the entry names into a textarea and specify "Save As Journal". Entry names can be indented so that a hierarchy appears in the table of contents, and so it is possible to go up a level, or to the next item on the same level (such as the next chapter). The editor ought to have a way to sort lines (this would probably be in the "helper" pane).
When reading a journal, there would be displayed along the top of the web page some navigation controls to go to the first, previous, next, or last page, or to the table of contents. You'd be able to go up a level, go to the next item on the same level, and search for an entry by name or by full text.
