I don't know about the sim, I was typed on the equipment already and current, so it was waived. I went through the process over 3 years ago. The knowledge test was based on questions from the FAA ATP exam. I think around 50 or so, all multiple choice... All I did was read the AIM/FAR before hand. You could also try reading through one of the FAA ATP study guides. Gleim, I think puts one out.
During the interview itself, there were 5 guys interviewing me, a mix of pilots and HR. They asked a couple of questions about Jepp approach plates, nothing tricky. There were a few scenario questions, what would you do if........ The majority of the interview consisted of them trying to get to know me, work history, experience. They asked what I knew of the Kingdom and the airline. How I thought my family would adjust, etc.
It was all very relaxed, all of the interviewers came across as good guys.
They gave ample opportunity to ask any questions that I had.