It's true that they are more interested in you than the RAF history, but make sure you know your history too. They can spot someone who is genuinely interested in a career in the service and those who are looking for a job. There are plenty of sites and books that cover the history, but i would mention if asked the history that is interesting to you. If it were me, I would read up on the first blooding of the RAF in the battle of Britain, the cold war cat and mouse games with the russian planes, and on the last vulcan mission during the falklands where they flew from the UK to the ascension islands and from there onto the falklands to bomb the airport at port stanley. Read the book 'Vulcan 607' by Rowland white, you wont be disappointed!