It's important to choose texts which are not too difficult for you. You need to be able to understand enough to get a grip on the rest of the language. Genre isn't really an issue, meaning what type of book it is. Even comic books or graphic novels as they're known for adults. Graphic novels can be brilliant because they support your understanding with the images. I love graphic novels in French and there are lots of good graphic novels that you can get in French. If other people like the books then why shouldn't you? Just check Amazon bestsellers or Waterstones.com for their current lists. Or you could try graded readers which are an excellent and underused resource