The books are along the lines of Harry Dresden series in Chicago, but this time in London with a policeman as the protagonist they have had really good reviews I have the first two Rivers of London and Moon over Soho on my soon to be read pile just waiting their turn. check them out on amazon or download a sample for kindle.
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)
I read the first book. It was fine, but it didn't grab me enough to read more. I'm more into Aaronovitch's work for Doctor Who. Hell, while discussing his New Adventures novel, The Also People (which he admitted was inspired by the Culture), he stated that talent borrows, genius steals, and Doctor Who writers get it off the back of a lorry, no questions asked...
I read the first four or five of Aaronovitch's Rivers of London series. They started all right, but the later ones weren't to my taste. I felt that they lost humor and strayed more into horror, and I chose to stop reading them.