Utilize the user interface (UI) to create domain model objects (Posts, Books, Reservations, etc), followed by monitoring the server-side Rails logs.
Examine the generated SQL and then directly access the database using either psql or the rails dbconsole.
Read the Models file (book.rb), search for associations, callbacks, scopes.
Lastly look up the most recent record that has been saved or added to the database rails c and play with it.