Von Smallhausen on page 2 of the thread has written an excellent summary of the sim ride from 2004, eight years on it hasn't changed, other than you now get to play with a 747, rather than a BAC 1-11. I would recommend taking on board on Von's pointers. Basically, it is a CRM/capacity/decision making exercise. Minimal use of automatics in a very basic mode allowed above transition level but otherwise all manual, all raw data. Rad Nav page of FMC is displayed, no other FMC functions are available. Expect to fly airways, and at least one hold and one NDB/VOR procedural approach over the two sectors. Time is short and your workload is high - work together effectively and make safe sensible decisions to get back on the ground and you are onto a winner.
My top tip - BA use TDODAR as the decision making tool in any non-normal/emergency situation. Make good use of it. Oh, and try and get to crane bank well ahead of the start time and spend an hour or so with your sim-buddy swapping notes and working out any differences in SOP between your respective airlines - makes life easier when the
hits the fan in the sim. And it will! All the best.