Helen, you will best appreciate TP's "Jingo"
from having read many of the other TP Discworld books beforehand.

"Jingo" has these central factors, with which it is
best to have some background familiarity and history.

The Patrician ... ah, shoot, what IS his name again?
The Night Watch. All of them out in force.
And, regarding the Night Watch,
Commander Vimes and his "Bingly-Bingly BEEP!"
Leonardo da Quirm plays a starring role, but you have to know who he is (introduced in that book about The Gonne).
Klatsch. Or is it Klatsh? can't remember.
The meddlesome aristocrats of Ankh.

This is one of TP's more involved plots.
But then, I am what Mudcatter Will Fly calls
A Bear of Little Brain,
and sometimes TP's plotting confuses the expletive deleted out of me.
Enjoy.