Invader Zim was not cancelled by the network. The creator pulled the copyright over a dispute on marketing and merchantice. In other words, he felt the network was making things he did not like, so he pulled the cartoon off the air.
In the Harper Connely series, the young woman can "feel" dead bodies when she is near them...a kind of "buzzing' goes on in her head. The closer to the corpse, the louder it gets. She can also "see" how that person died, but not the whole specifics. She runs a sevice to locate murdered or missing persons, but always runs into people who think she's a fraud. It's got a paranormal/detective feel to the stories.
By all means you should read them! There's so much they leave out ( and scramble up) in the TV show, that you will get more out of the original stories than what you see on HBO. There is also another Charlene Harris series about a girl named Harper who was struck by lightening as a child and can now "find" dead people. Good stuff!