I take it you're talking about HTML Help (CHM file).
What you/your users should also know about is the [F6] key.
This shifts focus within the application.
So, when the focus in in the ToC you use the up/down arrows
to move up/down (!) and the left/right arrows to open/close books.
When the highlight is on the topic you want to see press [Enter].
If the topic is longer than one screenful use [F6] to move the
focus into the topic and you can then scroll it with the up/down
arrows. Finally [F6] takes you back to the ToC and you can go to
another topic.
This sounds a lot more complex than it is; a few seconds
playing with [F6], [Enter] and the arrow keys and you should get
the hang of it.
--- Derek