They are very good Urban fantasy (along the lines of Dresden) with a good sense of humour. As an Aussie reading them, I'm not sure I got *all* the London/UK references, but I understood enough to really enjoy it (and had a great time walking around London recognising places referenced in the books).
There's 7 novels, a few novellas and several comics so far, so there's plenty of source material that a TV show could grow from. The comics are inside the continuity of the novels but separate enough stories, and I imagine that the TV show may do something similar - they might do some adapting of novel/novella/comic stories for the screen, but then they could also just add in other "crime of the week" stories in Peter's life which are entirely new and that'd work just as well.
I mostly started reading Rivers of London when Ben Aaronovitch was announced as a guest at the 2014 International Discworld Convention (which I attended) because I figured it'd be nice to know a bit about an author before meeting them - and the series - and Ben - did not disappoint. His panels at the con were great, and he's a huge Pratchett fan. There's the occasional Pratchett reference in the series (as he's made his protagonist, Peter Grant, also a Pratchett fan)