Take advantage of the free Mayor's Guide Tours when visiting Bath.  The guides do an excellent job of giving you the context of present-day Bath in the Abbey court yard which is conveniently located in front of both the Abbey and the Roman Baths.  The 2 hour tour walks you through past and present Bath with occaisonal references (and visuals) of what Bath was like in past centuries so that you can appreciate how much it was expanded and the role played by the major players.  The combination of past and present is particularly helpful because is provides a background and appreciation for the changes in British society first played out here - mixing of the social classes in the Assembly rooms where balls and gambling were the draw for both aristocrats and the affluent middle class to see and be seen.  The tour takes in the Royal Hospital (where patients were sent for treatment of pneumatic diseases and some skin diseases), the Assembly rooms, the Royal Crescent, the former city gates and the prominent parks.  By the end of the tour, the visitor can choose which of the many attractions (including the Jane Austen Centre) to return to.  Although the tour is totally without charge, it is an excellent introduce to a distinctive World Heritage site with many layers of history and activities.