I used the Airline Pilot Interviews book by Irv Jasinski that was a great book. It covers how a resume should look like as well as some interview questions that are generally asked by the airlines. It covers some of the technical, CRM, and HR stuff you might get asked during the interview as well as some interview tips. It's a good book for general knowledge of the ariline interview process.
I still think that the best way to prepare for an airline interview is to ask some of the pilots that interviewed for that particular airline. Most of the time the interview team at an airline asks the same set of questions to perspective pilots and even gives the exact same written multiple choice tests with the answers all the same.
When I interviewed at Island Air I really counted on what others said happened during their interview. So if you have a buddy that interviewed earlier and got a job with that airline go buy him or her a drink ask a bunch questions and take some notes.