Adding sympal_book_menu_module: This module adds your book_hierarchy automagically into your navigation. Very streightforward, and extremely simple. It provides no configuration, no database and so on. Just enable the module and refresh your menu's (cache).
The simplicity is its good part: You don't need to explain your users why the core book block dissapears on
several places, nor do you need to explain how to add menu items on each node.
That latter feature is in core, and it allows much more power. But it also disconnects things, such as the
book hierarchy and menu hierarchy. It disconnects the node titles from the menu titles. While for many these
are considered 'features', many people prefer simplicity. Another good reason why you may wat to use this
module, is that this one does not require you to hand out menu administration permissions: anyone who can
publish a book in the hierarchy will add it to the menu!