The Users Guide section of the BBS Online Help describes each module, screen and report in BBS and how they work.
There are some introduction topics and then the topics are broken up into sections for the Menu Menu, and the Reports Menu, and then each module and menu item as per the menu tree in BBS.
Use the Table of Contents to the left to navigate through the online help, or use the search option to search for one or more keywords to find the information you are looking for.