The main thing that's missing is not the manual/help file -- but a tutorial that walks you through a few tasks. Yes, the help file describes all the functions of the program. The problem is: Where do you start? The free-form interface of S&T can really be a shock to people who are used to standalone GPS navigation devices.
This Youtube video does a pretty decent job of showing you how to get started with navigation in Streets & Trips:
http://www.youtube.com/watch?v=ibuWdeYgTt0
That having been said, the helpfile
truly is the most comprehensive source of information about using the program. We've seen several cases of people coming to this forum with a basic question about using the program -- but the information is already in the help file (and comes up when you search for the most obvious term).
The problem is that S&T has a freeform interface, which is very different from the interface in standalone GPS navigation units. The helpfile is also written to explain the functions present in the freeform interface -- not to bridge the conceptual gap between standalone units and S&T.
S&T really needs to add a task-oriented interface, to cater to the new demographic of customers who are familiar with GPS navigation units.