I agree with what Drewski said but to add try to learn as many as you can and if you aren't doing a role where there are obvious ones you need to learn - eg. at least learning all the flying stations for pilot - then focus on learning all the main stations such as most of the large important flying stations (Brize, Waddington) and important stations for other reasons (Halton, Cranwell) plus more. Make sure you know all of the overseas ones as there are not that many. Finally, as Drewski alluded to think about the follow-up questions they will ask when doing your research. If you are going for pilot and you name drop Valley they'll expect you to know the aircraft and Sqns in Valley. If you're going for RAF Reg and you say Honington they'll ask what makes Honington important for the RAF Reg.