For an audition, you need to select a book that is fiction, has some dialogue in it, and is written for adults rather than children. Your selection should take about 8 minutes to read out loud. In most novels, that is about 4-5 pages. Practice your selection out loud before you come in for the audition. It does not matter if the book is new or old, well known or hardly anyone would have heard of it. You can start anywhere in the book. THE BEST THING TO DO IS CHOOSE SOMETHING YOU LIKE! Read in a conversational, natural tone with the emotion in your voice matching the content of the material. If you are very comfortable or experienced with creating character voices, and can be consistent with them, you can go ahead and do that. If not, it is better to not try to create character voices. It can be more of a distraction to a reader, than a help. You want the author's content to come alive for your listener.