All of the above plus the following:
Read quality papers. Get the Times and Telegraph every day including Sunday. Read the editorials and see what opinions they are proffering. As said before, read all about the world's hotspots, not just confined to where the RAF are involved, but current topics, like famine, the India/Pakistan conflict, etc.
Get on the net. Get into the habit of spending an hour each evening looking for info from, say, America to get their viewpoint (they're our closest allies and invariably lead nation in international conflict, especially against terrorism).
Also find out about and form an opinion on the military and the EU - it's a continuing subject and all about jointery at an international level.
Find out about joint service operations and procedure in the British Military. OK, you want to join the RAF, but are you aware, for example, the Army controls the RAF transport fleet? Or that the Harrier Force's primary job is close air support of the troops on the battlefield? Or that the E3D fleet is assigned to NATO, who have first call on the crews and assets? And so on.
Ok, so you've got a couple of months to prepare. Think about this: if you work yourself into the ground for the next 2 months, the preparation you will have done could set yourself up for a life in the biggest and most exclusive Club in the world - Professional Aviation. Worth sacrificing pub crawls, parties, visits home, etc. Explain to your girlfriend, too, what you're going to do and why, and she will understand that 2 months of neglect will pay vast dividends later.
Go for it and then knock them dead at CW.