Actually I have read one of the trilogy, I've read The Subtle Knife. It was alright, cant remember it much now but I didn't think it was all that amazing at the time I was reading it.
Oh, I honestly didn't find the books that great either, they would have been much more enjoyable to me as a teenager.
But compared to the film is another question. The film left out critical things, like the death of her friend at the end of the first book. The film should have included that.