I was fortunate in that I had some friends going through the process ahead of me so was able to glean off them the types of questions asked. I didn't use any specific interview books but know of others that did and found them useful. Beware though I have heard that some of the answers are actually wrong so rote learning might get you in hot water.
Your best bet would be to search pprune for a specific airline that you have an interview with and see what others are listing. Again beware that there might be nasty people trying to waste your time and put you off in the hope of beating you past the post. Then again as soon as a list gets published you can just about guarantee that any interviewers reading these pages will choose to ask something else!!
Some general things to consider though:-
- principles of flight eg: components of lift and drag
- difference between rate and angle of climb, VMCA, VMCG
- MET - what sort of weather you might expect in different fronts, different types of fog, jet streams, low viz operations and the requirements for things like a take off alternate, RVRs for each category
- airlaw - really a minefield here. Could get asked about RVSM, different classes of airspace
- jet engine theory, bypass engines, turbo prop theory if you head down that path
- specific stuff on the airline, employee numbers, key financials, route structure, aircraft, numbers, crewing, engines, range. Make sure you read all of their press releases and are up to date with share prices, fleet announcements etc.
- CRM (all the good stuff covered during your MCC). I got asked about communication and how come it is important in the cockpit. This lead to a discussion on how we communicate eg: body language, cultural differences etc etc
- have also heard of friends getting asked to give the principle of a VOR and NDB
Also be aware of topical matters that can come up at the time of interview or things specific to the aircraft type you are going to fly. Eg: Helios and the 737. This gives the interviewer an idea that you are well read.