Another pointer for people heading to the interviews -
Read up on current aviation news, and in particular, KA news!
Lastly, don't overdo your study on jets, make sure you spend time on other things too. HTBJ is totally hardcore stuff for people with little or no flying experience, since it was aimed at pilots transitioning from turboprops to jets. As I mentioned earlier, the primary focus should be on what you are expected to know, due to your background. On top of that, reading up on jets will be an extra bonus. As Flyer09 has mentioned, there is no way you can totally be prepared for what they will ask you. I feel the main point is not in giving an answer to all their technical questions, you just need to demonstrate that you have read up a bit about their jets to prove your enthusiasm. They are interviewing a cadet applicant, not a Direct Entry guy, and will not expect you to be a guru on jet systems.
Hope this helps, and good luck!!!