So as not to repeat the same stuff, see the posting "FedEx interview prep" on page 2 or 3, there's some good info there. Also search this forum for same, lots posted prior. The willflyforfood site always had great gouge but I haven't been there lately. I also read the prep book "mental math for pilots", good practice for shortcuts & tips on typical test questions.
As for advice, the sim prep may not be absolutely necessary, especially if you're flying a lot, you'll have to judge for yourself IRT your experience. It can't hurt though because you must pass the simulator to get to the interview. Obviously, think through all your "stories" well beforehand. At the interview itself, just try to relax and most importantly, be yourself. They will see right through canned answers and "borrowed" stories so be honest, confident and sure of yourself and your abilities. Normally it's a 2v1 with 2 line Captains. Personally I found the interview extremely professional, on the mark (pilot-to-pilot, not a lot of BS) and an overall great experience. Good luck, hope to see you in MEM!